[gnome-photos/gnome-3-24] build: Bump minimum GTK+ version to 3.22.15

[Debarshi Ray <debarshir src gnome org>]

commit f189f975700bd11b872938a72a13f51abe7ae028
Author: Debarshi Ray <debarshir gnome org>
Date:   Mon Jun 12 23:43:08 2017 +0200

    build: Bump minimum GTK+ version to 3.22.15
    
    We need it for the new entry-tag CSS style class that we rely on since
    commit b1a11799a167ac9043c7860a21ee8e61a5db6c94

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 593c40a..bbc7466 100644
--- a/configure.ac
+++ b/configure.ac
@@ -43,7 +43,7 @@ GFBGRAPH_MIN_VERSION=0.2.1
 GLIB_MIN_VERSION=2.44.0
 GOA_MIN_VERSION=3.8.0
 GRILO_MIN_VERSION=0.3.0
-GTK_MIN_VERSION=3.22.10
+GTK_MIN_VERSION=3.22.15
 
 AX_REQUIRE_DEFINED([IT_PROG_INTLTOOL])
 IT_PROG_INTLTOOL([0.50.1])