Require gio-2.0 in pkg-config file
Require gio-2.0 in pkg-config file

Without this, app developer will have to explicitly add
`pkg-config --libs gio-2.0` to linker flags.

weynhamz/GNOME-libgit2-glib,GNOME/libgit2-glib,weynhamz/GNOME-libgit2-glib,weynhamz/GNOME-libgit2-glib,chergert/libgit2-glib,chergert/libgit2-glib,weynhamz/GNOME-libgit2-glib,chergert/libgit2-glib,GNOME/libgit2-glib