Converted a queue warning into a debug message in job adapter

This warning is printed often for users who do not define the queue in the submit script, this is a normal/allowed use case and the warning isn't appropriate

arc/job/adapter.py

@@ -518,7 +518,8 @@ def write_submit_script(self) -> None:
         }
 
         if queue is None:
-            logger.warning(f'Queue not defined for server {self.server}. Assuming the queue name is defined in your submit.py script.')
+            logger.debug(f'Queue not defined for server {self.server}. '
+                         f'Assuming the queue name is defined in your submit.py script.')
             del format_params['queue']
 
         try: