devel/git: Fix build if devel/libsysinfo is installed
Add option SYSINFO - default off.
While here fix warning:
Warning: www/p5-CGI was in Perl CORE. Check with `corelist CGI 0` and `corelist -a CGI` if it should be conditionally added depending on PERL_LEVEL
PR: 287680
Approved by: garga (maintainer)