Launcher: disabling plugin files is broken
Steps to reproduce:
- Open the launcher and enable a plugin.
- Close the launcher.
- Open the launcher and disable that plugin.
- Re-open the launcher and observe that the plugin you disabled has re-enabled itself.
(RM-2173 from redmine: created on 2014-11-30 by scrawl ., , closed on 2014-12-01 by scrawl .)