nixos/lighttpd-service: don't use types.string (it's deprecated)

nixos/modules/services/web-servers/lighttpd/default.nix

···
 
       document-root = mkOption {
         default = "/srv/www";
-        type = types.str;
+        type = types.path;
         description = ''
           Document-root of the web server. Must be readable by the "lighttpd" user.
         '';
···
 
       configText = mkOption {
         default = "";
-        type = types.string;
+        type = types.lines;
 	example = ''...verbatim config file contents...'';
         description = ''
           Overridable config file contents to use for lighttpd. By default, use
···
 
       extraConfig = mkOption {
         default = "";
-        type = types.string;
+        type = types.lines;
         description = ''
           These configuration lines will be appended to the generated lighttpd
           config file. Note that this mechanism does not work when the manual