Handle NULL connect field

Author: sfodagain

source/v5/mqtt5_options_storage.c

@@ -3730,8 +3730,10 @@ void aws_mqtt5_client_options_storage_destroy(struct aws_mqtt5_client_options_st
     aws_tls_connection_options_clean_up(&options_storage->tls_options);
     aws_http_proxy_config_destroy(options_storage->http_proxy_config);
 
-    aws_mqtt5_packet_connect_storage_clean_up(options_storage->connect);
-    aws_mem_release(options_storage->connect->allocator, options_storage->connect);
+    if (options_storage->connect != NULL) {
+        aws_mqtt5_packet_connect_storage_clean_up(options_storage->connect);
+        aws_mem_release(options_storage->connect->allocator, options_storage->connect);
+    }
 
     aws_mem_release(options_storage->allocator, options_storage);
 }