fix src.url typos

pkgs/development/libraries/libipfix/default.nix

···
   name = "libipfix-${version}";
   version = "110209";
   src = fetchurl {
-    url = " http://sourceforge.net/projects/libipfix/files/libipfix/libipfix_110209.tgz";
+    url = "http://sourceforge.net/projects/libipfix/files/libipfix/libipfix_110209.tgz";
     sha256 = "0h7v0sxjjdc41hl5vq2x0yhyn04bczl11bqm97825mivrvfymhn6";
   };
   meta = with stdenv.lib; {

pkgs/tools/cd-dvd/nrg2iso/default.nix

···
   version = "0.4";
 
   src = fetchurl {
-    url = "gregory.kokanosky.free.fr/v4/linux/${name}.tar.gz";
+    url = "http://gregory.kokanosky.free.fr/v4/linux/${name}.tar.gz";
     sha256 = "18sam7yy50rbfhjixwd7wx7kmfn1x1y5j80vwfxi5v408s39s115";
   };
 

pkgs/top-level/python-packages.nix

···
     version = "2.1.1";
 
     src = pkgs.fetchurl {
-      url = " mirror://pypi/p/python-daemon/${name}.tar.gz";
+      url = "mirror://pypi/p/python-daemon/${name}.tar.gz";
       sha256 = "17v80qb98p1gv4j9mq6wb55cv7hc4j1hzw5y2f4s5hrpxs3w3a2q";
     };