fix: save options after updating them

_optionsUtil.save() is only called in _saveOptions, which is only
called through

- _onApiSetAllSettings
- _onApiModifySettings
- _onCommandToggleTextScanning

it should be safe to simply save settings after updating them.

without saving, the options will be updated every time the background
restarts, until any settings are modified or text scanning is
toggled. for _updateVersion21, this means the welcome page will open
repeatedly to show the same warning.

ext/js/data/options-util.js

@@ -114,6 +114,7 @@ class OptionsUtil {
 
         if (typeof options !== 'undefined') {
             options = await this.update(options);
+            await save(options);
         } else {
             options = this.getDefault();
         }