doc/ffserver: remove more pointless/outdated entries

Mentioning build options, or bugs, or mysterious limitations should not
be done in the manual.

doc/ffserver.texi

@@ -109,24 +109,6 @@ You should edit the ffserver.conf file to suit your needs (in terms of
 frame rates etc). Then install ffserver and ffmpeg, write a script to start
 them up, and off you go.
 
-@section Troubleshooting
-
-@subsection The audio and video lose sync after a while.
-
-Yes, they do.
-
-@subsection After a long while, the video update rate goes way down in WMP.
-
-Yes, it does. Who knows why?
-
-@subsection WMP 6.4 behaves differently to WMP 7.
-
-Yes, it does. Any thoughts on this would be gratefully received. These
-differences extend to embedding WMP into a web page. [There are two
-object IDs that you can use: The old one, which does not play well, and
-the new one, which does (both tested on the same system). However,
-I suspect that the new one is not available unless you have installed WMP 7].
-
 @section What else can it do?
 
 You can replay video from .ffm files that was recorded earlier.