Task #49162: Rewrite install tool
Don't write LocalConfiguration on every Install Tool entry
Silent Updater "removeObsoleteLocalConfigurationSettings" will always kick in and save the current LocalConfiguration even if nothing has to be changed.
If you have a non-writeable LocalConfiguration.php you will then end up in an Exception in this step already, without the installer having a chance to kick in and handle it in a more "gentle" way (needs improvements too, will need some further issues).
[BUGFIX] Don't write LocalConfiguration on every Install Tool entry
Make removeObsoleteLocalConfigurationSettings only rewrite the
file if something has changed.
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring