Makefile.PL: changed location of Git repo/web page
Makefile.PL: changed location of Git repo/web page

- GNOME Git repos are now hosted in a GitLab instance, updated URIs

GNOME/perl-Glib-Object-Introspection,cpanxaoc/perl-Glib-Object-Introspection,cpanxaoc/perl-Glib-Object-Introspection,GNOME/perl-Glib-Object-Introspection