Fix build with older clang compilers
https://bugzilla.gnome.org/show_bug.cgi?id=720708
https://github.com/GNOME/glib/commit/ab9f63fadd8f769b2b2ae7c32a8cce42fac01451
--- glib/glib/gmessages.c.orig 2016-04-11 16:39:26.000000000 -0500
+++ glib/glib/gmessages.c 2017-08-11 11:31:55.000000000 -0500
const char *pretty_function,
- ? "file %s: line %d (%s): assertion failed: (%s)"
- : "file %s: line %d (%s): should not be reached",
+ "file %s: line %d (%s): assertion failed: (%s)",
+ "file %s: line %d (%s): should not be reached",