License of OpenWeatherMap-provided data in about dialog is wrong

[triallax]

According to https://openweathermap.org/full-price, for the free tier, the "License for data and database" is ODbL (to be more accurate, I believe the database is under the ODbL, but the data is under the DbCL; however, it's probably best if you contact OpenWeather to make sure).

However, the current Forecastie about dialog states that "Data provided by OpenWeatherMap, under the Creative Commons CC-BY-SA 2.0 licence," which I also vaguely recall reading someday from somewhere online, but the linked OpenWeatherMap page expressly states otherwise.

[robinpaulson]

@martykan