Ensure server_aliases is of type list instead of dict_keys in Py3+

This resolves an issue where otherwise `lib.imprint` will fail on `self.data` for this Creator plug-in

openpype/hosts/maya/plugins/create/create_render.py

@@ -254,7 +254,7 @@ def _create_render_settings(self):
  # get pools
  pool_names = []
 
- self.server_aliases = self.deadline_servers.keys()
+ self.server_aliases = list(self.deadline_servers.keys())
  self.data["deadlineServers"] = self.server_aliases
  self.data["suspendPublishJob"] = False
  self.data["review"] = True