PR to update weewx.service to wait for MariaDB or MySQL before starting

[John Smith]

I posted a proposed PR to update the SystemD service file that gets installed via weeWX packages:

https://github.com/weewx/weewx/pull/1030

One of the comments opposing the change was that they have MariaDB or MySQL installed but use SQLite with weeWX.

Does anyone know how much delay there would be in this situation?

I made the PR after noticing weeWX exiting after it tried to connect to MariaDB but because weeWX was started before MariaDB was ready and weeWX didn't wait and retry at all, it just exited.

I intentionally used "Wants=" instead of "Requires=" so that if MariaDB or MySQL don't have a service file SystemD will immediately start weeWX.