cast port to int

app.py

@@ -44,7 +44,7 @@ else:
     hivemq_host = os.getenv("host")
     hivemq_username = os.getenv("username")
     hivemq_password = os.getenv("password")
-    hivemq_port = os.getenv("port")
+    hivemq_port = int(os.getenv("port"))
     reactor = os.getenv("reactor")
 
     # button to submit the form