Add button sometimes adds to every trimester

[derdilla]

Steps:

1. start with new app install (default settings, other shool system)
2. add subject (through settings after initial dialog)
3. add value

Result: All trimesters seem to share the same data source

version: 2.5.0

[FauconSpartiate]

Nice catch 👍🏻

[FauconSpartiate]

@NobodyForNothing A workaround in the meantime until I release this fix is to close and reopen the app after adding the subject. They won't be linked between terms anymore after the restart.