don't segfault after starting sofia, upon xml_open_config lookup failure for the…

don't segfault after starting sofia, upon xml_open_config lookup failure for the profile from launch_sofia_worker_thread

src/mod/endpoints/mod_sofia/sofia.c

@@ -2252,7 +2252,11 @@ void *SWITCH_THREAD_FUNC sofia_profile_thread_run(switch_thread_t *thread, void
 	sofia_clear_pflag_locked(profile, PFLAG_SHUTDOWN);
 	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Waiting for worker thread\n");
 
-	switch_thread_join(&st, worker_thread);
+	if ( worker_thread ) {
+		switch_thread_join(&st, worker_thread);
+	} else {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "ERROR: Sofia worker thead failed to start\n");
+	}
 
 	sanity = 4;
 	while (profile->inuse) {

src/switch_apr.c

@@ -1169,6 +1169,11 @@ SWITCH_DECLARE(switch_status_t) switch_thread_exit(switch_thread_t *thd, switch_
  */
 SWITCH_DECLARE(switch_status_t) switch_thread_join(switch_status_t *retval, switch_thread_t *thd)
 {
+	if ( !thd ) {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "ERROR: Attempting to join thread that does not exist\n");
+		return SWITCH_STATUS_FALSE;
+	}
+
 	return apr_thread_join((apr_status_t *) retval, (apr_thread_t *) thd);
 }