core: 2021.4.0 - OpenWeather integration broken - unsupported operand type(s) for /: 'NoneType' and 'int';

The problem

After upgrade to 2021.4.0 OpenWeather integration is unable to start

 Config entry 'OpenWeatherMap' for openweathermap integration not ready yet: unsupported operand type(s) for /: 'NoneType' and 'int'; Retrying in background

What is version of Home Assistant Core has the issue?

2021.4.0

What was the last working version of Home Assistant Core?

2021.3.3

What type of installation are you running?

Home Assistant Container

Integration causing the issue

OpenWeatherMap

Link to integration documentation on our website

https://www.home-assistant.io/integrations/openweathermap/

Example YAML snippet

No response

Anything in the logs that might be useful for us?

Config entry 'OpenWeatherMap' for openweathermap integration not ready yet: unsupported operand type(s) for /: 'NoneType' and 'int'; Retrying in background