language change resets Text Style option

[zetok]

Brief Description

When language in settings is changed, it resets Text Style format to Plaintext

OS: Gentoo Linux amd64
qTox version: v1.5.2-144-gbbdd4f0
Commit hash: bbdd4f0
toxcore: 0.0.0
Qt: 5.6.1

Reproducible: Always

Steps to reproduce

1. Set Text Style format setting to something other than Plaintext
2. Change language

Observed Behavior

Text Style format is reset to Plaintext

Expected Behavior

Text Style format setting shouldn't be affected by change of other settings

[zetok]

Note: also happens due to Logout after changing the setting.