Lets see if this way works to remove all capabilities from the list

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2688 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/h323/ast_h323.cpp

@@ -858,7 +858,8 @@ int h323_set_capability(int cap, int dtmfMode)
 		return 1;
 	}
 
-//	endPoint->RemoveCapabilities("ALL");
+	/* clean up old capabilities list before changing */
+	endPoint->RemoveCapabilities(PStringArray("All"));
 
 	mode = dtmfMode;
 	if (dtmfMode == H323_DTMF_INBAND) {