refine code

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@3006 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/codecs/mod_gsm/mod_gsm.c

@@ -136,6 +136,7 @@ static const switch_codec_implementation_t gsm_8k_implementation = {
 		/*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, 
 		/*.ianacode */ 3, 
 		/*.iananame */ "gsm", 
+		/*.fmtp */ NULL,
 		/*.samples_per_second */ 8000, 
 		/*.bits_per_second */ 13200, 
 		/*.microseconds_per_frame */ 20000,