Merge pull request #3635 from DataDog/scottdixon/pdh_tags_fix

Fix issue with creating tags from conf in IIS

checks/libs/win/pdhbasecheck.py

@@ -33,7 +33,7 @@ def __init__(self, name, init_config, agentConfig, instances, counter_list):
 
                 cfg_tags = instance.get('tags')
                 if cfg_tags is not None:
-                    tags = cfg_tags.join(",")
+                    tags = ",".join(cfg_tags)
                     self._tags[key] = list(tags) if tags else []
                 remote_machine = None
                 host = instance.get('host')