Fix in $_protected array of register_globals security procedure

* Followup to b78a8c7d40446a3e2e36772706662fd033fe7d1d
* Just FYI, renamed to "system_path" in 0c1e405437ceb3c1888e151e6a400653310ad6c1
#3005
Merge pull request #3006 from vlakoff/security

Fix in $_protected array of register_globals security procedure