[gtk+] Drop another unused script

[Matthias Clasen <matthiasc src gnome org>]

commit 2d46db1b8308f7a60c94e94864576642cbe897ed
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Sep 4 00:24:00 2014 -0400

    Drop another unused script
    
    The check engine abi script was never used in our build, and
    with engines being on the way out, lets drop this.

 gtk-engine-check-abi.sh |   30 ------------------------------
 1 files changed, 0 insertions(+), 30 deletions(-)