Sample modules.conf: comment out example load statement.

The sample modules.conf explicitly loaded res_musiconhold.so.  This is
redundent as autoload=yes is already set.  It causes warnings if
res_musiconhold.so was not installed and results in an unexpected load
if the admin disables autoload without remembering to remove the
res_musiconhold load statement.

Also remove reference to unknown module pbx_gtkconsole.

Change-Id: Ib01888994d9f1364b14d3c9fb6ff96774a6e580a

configs/samples/modules.conf.sample

@@ -29,12 +29,7 @@ autoload=yes
 ; If you want you can combine with preload
 ; preload-require = res_odbc.so
 ;
-; If you want, load the GTK console right away.
-;
-noload => pbx_gtkconsole.so
-;load => pbx_gtkconsole.so
-;
-load => res_musiconhold.so
+;load => res_musiconhold.so
 ;
 ; Load one of: chan_oss, alsa, or console (portaudio).
 ; By default, load chan_oss only (automatically).