theora: fix packetizer fourcc

This prevented restreaming theora streams into ogg
Signed-off-by: Rafaël Carré <rafael.carre@gmail.com>
(cherry picked from commit 195355bee28c1307f243f138e574525868514720)
Signed-off-by: Pierre Ynard <linkfanel@yahoo.fr>

modules/codec/theora.c

@@ -250,6 +250,7 @@ static int ProcessHeaders( decoder_t *p_dec )
     }
 
     /* Set output properties */
+    if( !p_sys->b_packetizer )
     switch( p_sys->ti.pixelformat )
     {
       case OC_PF_420: