firebase admin database url wrong check

[Halo07]

• Operating System version: windows 10
• Firebase SDK version: 4.5.0
• Python version: 3.8
• Firebase Product: database

Realtime database end with "firebasedatabase.app" and in the "db.py" at line 834 is:
if parsed_url.netloc.endswith('.firebaseio.com'): return cls._parse_production_url(parsed_url, emulator_host)

This return the error: "Database URL must be a valid URL to a Firebase Realtime Database instance" even if you use the right link of the Realtime Database

[lahirumaramba]

Duplicate of #514