fix:firebase_init reorder

python/subscribe_to_topic.py

@@ -2,12 +2,17 @@
 from firebase_admin import credentials, messaging
 import os
 
+# retreive key from env
+key = eval(os.environ['KEY'])
+
+# check if app is alr initialized
+try:
+    app = firebase_admin.get_app()
+except ValueError as e:
+    cred = credentials.Certificate(key)
+    firebase_admin.initialize_app(cred)
+
 def main(context):
-    key = eval(os.environ['KEY'])
-    if 'timetable_app' not in firebase_admin._apps:
-        cred = credentials.Certificate(key)
-        firebase_admin.initialize_app(cred, name='timetable_app')
-    context.log(key)
     if (context.req.path == "/"):
         return context.res.json({"msg": "working, use /subscribe to register users"})
     if (context.req.path == "/subscribe"):