Fix potential bug. THanks luigi!

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@32089 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -7329,12 +7329,8 @@ static int get_refer_info(struct sip_pvt *transferer, struct sip_request *outgoi
 			ast_uri_decode(referdata->replaces_callid);
 			if ((ptr = strchr(referdata->replaces_callid, ';'))) 	/* Remove options */ {
 				*ptr = '\0';
+				ptr++;
 			}
-			/*
-			 * XXX don't know what was the intention but this code is
-			 * definitely wrong, as ptr can be NULL here.
-			 */
-			ptr++;
 
 			/* Find the different tags before we destroy the string */
 			to = strcasestr(ptr, "to-tag=");