fdo#56832 Explicitly mention Ogg Audio and Video

.ogx is also a valid extension, see http://wiki.xiph.org/MIME_Types_and_File_Extensions

Change-Id: Ieb5f3b7016b58beaf915673181369530a3d0709e
Reviewed-on: https://gerrit.libreoffice.org/3609Reviewed-by: Tor Lillqvist <tml@iki.fi>
Tested-by: Tor Lillqvist <tml@iki.fi>

avmedia/source/viewer/mediawindow.cxx

@@ -223,7 +223,8 @@ void MediaWindow::getMediaFilters( FilterNameVector& rFilterNameVector )
                                       "MIDI Audio", "mid;midi",
                                       "MPEG Audio", "mp2;mp3;mpa",
                                       "MPEG Video", "mpg;mpeg;mpv;mp4",
-                                      "Ogg bitstream", "ogg;oga;ogv",
+                                      "Ogg Audio", "ogg;oga;",
+                                      "Ogg Video", "ogv;ogx;",
                                       "Quicktime Video", "mov",
                                       "Vivo Video", "viv",
                                       "WAVE Audio", "wav",