Make sure terminate/2 is called in config

The callback was not called as we didn't trap exits. This is not a big deal at
runtime, as the process would go down anyway after config app terminates, and
even if it restarts, we'd clean up all the config values anyway in init.
However, when running tests this could leave config value set from the previous
config app run.

Author: nickva

src/config/src/config.erl

@@ -276,6 +276,8 @@ subscribe_for_changes(Subscription) ->
     config_notifier:subscribe(Subscription).
 
 init(IniFilesDirs) ->
+    % trap exits to make sure terminate/2 gets called
+    process_flag(trap_exit, true),
     enable_early_features(),
     erase_all(),
     IniFiles = expand_dirs(IniFilesDirs),