Add patch for compatibility with glib 2.59

Could you also ping upstream to review https://gitlab.gnome.org/GNOME/perl-glib/merge_requests/1 ?

This fixes the build in Ubuntu 19.04.

You can see the autopkgtest failure at:

https://autopkgtest.ubuntu.com/packages/libg/libglib-perl/disco/amd64

excerpt

not ok 18
#   Failed test at t/g.t line 87.
#          got: 'some string'
#     expected: 'some string
# '