define _TP_COMPILATION in gir scanner
define _TP_COMPILATION in gir scanner

Otherwise upcoming single-include #error will break the scanner

https://bugs.freedesktop.org/show_bug.cgi?id=49384

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib