FS-4582 --resolve

src/mod/endpoints/mod_sofia/mod_sofia.c

@@ -381,6 +381,7 @@ switch_status_t sofia_on_destroy(switch_core_session_t *session)
 			switch_yield(100000);
 		}
 
+		if (!zstr(tech_pvt->call_id)) {
 			switch_mutex_lock(tech_pvt->profile->flag_mutex);
 			if ((uuid = switch_core_hash_find(tech_pvt->profile->chat_hash, tech_pvt->call_id))) {
 				free(uuid);
@@ -388,7 +389,7 @@ switch_status_t sofia_on_destroy(switch_core_session_t *session)
 				switch_core_hash_delete(tech_pvt->profile->chat_hash, tech_pvt->call_id);
 			}
 			switch_mutex_unlock(tech_pvt->profile->flag_mutex);
-
+		}
 
 		if (switch_core_codec_ready(&tech_pvt->read_codec)) {
 			switch_core_codec_destroy(&tech_pvt->read_codec);