build: Bump GTK+ requirement

GTK_POLICY_EXTERNAL requires at least 3.15.0

diff --git a/configure.ac b/configure.ac
index 3a9e3ff2cf28b5ab0f2975af7c653cb118e65212..d55848b7b8f8515010247c7b2f26add434103872 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -77,7 +77,7 @@ CLUTTER_MIN_VERSION=1.15.90
 GOBJECT_INTROSPECTION_MIN_VERSION=0.10.1
 GJS_MIN_VERSION=1.39.0
 MUTTER_MIN_VERSION=3.15.1
-GTK_MIN_VERSION=3.13.2
+GTK_MIN_VERSION=3.15.0
 GIO_MIN_VERSION=2.37.0
 LIBECAL_MIN_VERSION=3.5.3
 LIBEDATASERVER_MIN_VERSION=3.5.3