[fix/connection/tasks] Ignore current task instance when checking active tasks - #1204

The _is_update_in_progress function was incorrectly detecting the current Celery task as another running task, causing update_config to exit early. This fix excludes the current task by comparing task IDs, ensuring only other instances for the same device are considered. Added tests to cover same worker (should not skip) and different worker (should skip) scenarios.

Fixes #1204

Author: piyushdev04

openwisp_controller/connection/tasks.py

@@ -20,7 +20,7 @@ def _is_update_in_progress(device_id):
     active = current_app.control.inspect().active()
     if not active:
         return False
-    current_task_id = getattr(current_task, 'request', None)
+    current_task_id = getattr(current_task, "request", None)
     if current_task_id:
         current_task_id = current_task_id.id
     else: