Bug#426426: SetEnv PERL5LIB ... cleaned by suEXEC

[Anders Kaseorg <andersk@MIT.EDU>]

I don't think PERL5LIB can be added to the suexec safe list.  The goal
of suexec is to protect users from a malicious/compromised httpd, but if
httpd can set PERL5LIB, it can run arbitrary code as the user.

I would like there to be a solution for this, but it needs to be handled
on the Perl side.