corrected time format in query

cdplib/db_handlers/InfluxdbHandler.py

@@ -110,7 +110,7 @@ class InfluxdbHandler:
             start = datetime.strftime(start, format="%Y-%m-%dT%H:%M:%SZ")
 
         if not isinstance(stop, str):
-            start = datetime.strftime(stop, format="%Y-%m-%dT%H:%M:%SZ")
+            stop = datetime.strftime(stop, format="%Y-%m-%dT%H:%M:%SZ")
 
         query = 'SELECT ' +\
                 columns +\