Implement a additional condition for 366 issue

Author: Gonchik Tsymzhitov

atlassian/rest_client.py

@@ -134,7 +134,7 @@ def request(self, method='GET', path='/', data=None, flags=None, params=None, he
         if flags:
             url += ('&' if params else '') + '&'.join(flags or [])
         if files is None:
-            data = json.dumps(data)
+            data = None if not data else json.dumps(data)
 
         headers = headers or self.default_headers
         response = self._session.request(