core: typo fix

- ';' after if() (again). Fortunately it didn't have any impact
  since right now nobody returns NONSIP_MSG_ACCEPT from a
  nonsip_msg callback.

receive.c

@@ -127,7 +127,7 @@ int receive_msg(char* buf, unsigned int len, struct receive_info* rcv_info)
 
 	if (msg->first_line.type==SIP_REQUEST){
 		if (!IS_SIP(msg)){
-			if (nonsip_msg_run_hooks(msg)!=NONSIP_MSG_ACCEPT);
+			if (nonsip_msg_run_hooks(msg)!=NONSIP_MSG_ACCEPT)
 				goto end; /* drop the message */
 		}
 		/* sanity checks */