Deleting a logger does not restore the loggin configuration

Steps to reproduce:
1. go to http://server/hudson/log/new
2. create logger aaa
3. in http://server/hudson/log/aaa/configure, add a logger (for instance:
hudon, FINEST)
4. on http://server/hudson/log/aaa/ observe in awe the logging statement
5. delete the logger on http://server/hudson/log/aaa/delete

Expected result:
1. the modification introduced by the aaa logger to j.u.l configuration are
reverted

Obtained result:
1. The logging screen is removed, but the j.u.l configuration is left untouched

Workaround:
1. before deleting a logger, change all the logging levels to what they should
have been without this hudson logger, then save, then delete