Update plugin.py

Author: wj-Mcat

src/wechaty/plugin.py

@@ -277,7 +277,11 @@ def add_interval_job(
             job_id = f'interval-job-{minutes}'
 
         job_id = str(job_id)
-
+        
+        job = self.scheduler.get_job(job_id=job_id)
+        if job is not None:
+            self.scheduler.remove_job(job_id=job_id)
+            
         trigger = IntervalTrigger(
             minutes=minutes
         )