Documentation/isdn: check and fix dead links ...

and switch to https where possible.

All links have been eyeballed to verify that the domains have
not changed, etc.

Signed-off-by: Sanjeev Gupta <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/isdn/INTERFACE.CAPI

···
 directions between the application and the hardware driver.
 
 Format and semantics of CAPI messages are specified in the CAPI 2.0 standard.
-This standard is freely available from http://www.capi.org.
+This standard is freely available from https://www.capi.org.
 
 
 2. Driver and Device Registration

Documentation/isdn/README

···
      de.alt.comm.isdn4linux
 
   There is also a well maintained FAQ in English available at
-     http://www.mhessler.de/i4lfaq/
+     https://www.mhessler.de/i4lfaq/
   It can be viewed online, or downloaded in sgml/text/html format.
   The FAQ can also be viewed online at
-     http://www.isdn4linux.de/faq/
+     https://www.isdn4linux.de/faq/i4lfaq.html
   or downloaded from
      ftp://ftp.isdn4linux.de/pub/isdn4linux/FAQ/
 

Documentation/isdn/README.FAQ

···
 
 In case you just want to see the FAQ online, or download the newest version,
 you can have a look at my website:
-http://www.mhessler.de/i4lfaq/ (view + download)
+https://www.mhessler.de/i4lfaq/ (view + download)
 or:
-http://www.isdn4linux.de/faq/ (view)
+https://www.isdn4linux.de/faq/4lfaq.html (view)
 
 As the extension tells, the FAQ is in SGML format, and you can convert it
 into text/html/... format by using the sgml2txt/sgml2html/... tools.

Documentation/isdn/README.gigaset

···
         T-Com Sinus 721 data
         Chicago 390 USB (KPN)
 
-     See also http://www.erbze.info/sinus_gigaset.htm and
-              http://gigaset307x.sourceforge.net/
+     See also http://www.erbze.info/sinus_gigaset.htm
+       (archived at https://web.archive.org/web/20100717020421/http://www.erbze.info:80/sinus_gigaset.htm ) and
+	http://gigaset307x.sourceforge.net/
 
      We had also reports from users of Gigaset M105 who could use the drivers
      with SX 100 and CX 100 ISDN bases (only in unimodem mode, see section 2.5.)
···
      to use CAPI 2.0 or ISDN4Linux for ISDN connections (voice or data).
 
      There are some user space tools available at
-     http://sourceforge.net/projects/gigaset307x/
+     https://sourceforge.net/projects/gigaset307x/
      which provide access to additional device specific functions like SMS,
      phonebook or call journal.
 
···
      You can use some configuration tool of your distribution to configure this
      "modem" or configure pppd/wvdial manually. There are some example ppp
      configuration files and chat scripts in the gigaset-VERSION/ppp directory
-     in the driver packages from http://sourceforge.net/projects/gigaset307x/.
+     in the driver packages from https://sourceforge.net/projects/gigaset307x/.
      Please note that the USB drivers are not able to change the state of the
      control lines. This means you must use "Stupid Mode" if you are using
      wvdial or you should use the nocrtscts option of pppd.
···
      ---------------------------
      If you can't solve problems with the driver on your own, feel free to
      use one of the forums, bug trackers, or mailing lists on
-         http://sourceforge.net/projects/gigaset307x
+         https://sourceforge.net/projects/gigaset307x
      or write an electronic mail to the maintainers.
 
      Try to provide as much information as possible, such as
···
 4.   Links, other software
      ---------------------
      - Sourceforge project developing this driver and associated tools
-         http://sourceforge.net/projects/gigaset307x
+         https://sourceforge.net/projects/gigaset307x
      - Yahoo! Group on the Siemens Gigaset family of devices
-         http://de.groups.yahoo.com/group/Siemens-Gigaset
+         https://de.groups.yahoo.com/group/Siemens-Gigaset
      - Siemens Gigaset/T-Sinus compatibility table
          http://www.erbze.info/sinus_gigaset.htm
+	    (archived at https://web.archive.org/web/20100717020421/http://www.erbze.info:80/sinus_gigaset.htm )
 
 
 5.   Credits