Only trigger warning about project_name if it's being set to something

that isn't `None`.

Author: hategan

src/psij/job_attributes.py

@@ -166,6 +166,7 @@ def project_name(self) -> Optional[str]:
 
     @project_name.setter
     def project_name(self, project_name: Optional[str]) -> None:
-        logger.warning('The "project_name" attribute is deprecated. Please use the "account" '
-                       'attribute instead.')
+        if project_name is not None:
+            logger.warning('The "project_name" attribute is deprecated. Please use the "account" '
+                           'attribute instead.')
         self.account = project_name