fix str to tuple (librenms#18434)

Author: Serazio

LibreNMS/queuemanager.py

@@ -362,11 +362,11 @@ def do_dispatch(self):
     def do_work(self, run_type, group):
         if run_type == "poll":
             logger.info("Polling billing")
-            args = ("-d", "-f") if self.config.debug else ("-f")
+            args = ("-d", "-f") if self.config.debug else ("-f",)
             exit_code, output = LibreNMS.call_script("poll-billing.php", args)
         else:  # run_type == 'calculate'
             logger.info("Calculating billing")
-            args = ("-d", "-f") if self.config.debug else ("-f")
+            args = ("-d", "-f") if self.config.debug else ("-f",)
             exit_code, output = LibreNMS.call_script("billing-calculate.php", args)
 
         if exit_code != 0: