fix spaces

response_db.py

@@ -5,9 +5,9 @@ import os
 class ResponseDb:
     def __init__(self):
         # Set up the connection
-        mongodb_username = os.environ['mongodb_username']
-        mongodb_pw = os.environ['mongodb_pw']
-        mongodb_cluster_url = os.environ['mongodb_cluster_url']
+        mongodb_username=os.environ['mongodb_username']
+        mongodb_pw=os.environ['mongodb_pw']
+        mongodb_cluster_url=os.environ['mongodb_cluster_url']
         self.client = MongoClient(f"mongodb+srv://{mongodb_username}:{mongodb_pw}@{mongodb_cluster_url}/?retryWrites=true&w=majority")
         self.db = self.client['vqa-game']
         self.collection = self.db['vqa-game']