Provide a better name for the mono downmixer

modules/audio_filter/channel_mixer/mono.c

@@ -99,7 +99,7 @@ static const char *const ppsz_pos_descriptions[] =
  * Module descriptor
  *****************************************************************************/
 vlc_module_begin ()
-    set_description( N_("Audio filter for stereo to mono conversion") )
+    set_description( N_("Stereo to mono downmixer") )
     set_capability( "audio filter", 0 )
     set_category( CAT_AUDIO )
     set_subcategory( SUBCAT_AUDIO_AFILTER )