[gnome-builder] build: bump gtksourceview required version

[Christian Hergert <chergert src gnome org>]

commit 7e3291800307e5b3f15c1f356ebd8442a67f533d
Author: Christian Hergert <christian hergert me>
Date:   Mon Sep 14 23:19:16 2015 -0700

    build: bump gtksourceview required version
    
    We rely on new stuff like get_icon_name.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e58a998..fb16f41 100644
--- a/configure.ac
+++ b/configure.ac
@@ -145,7 +145,7 @@ dnl Check for Required Packages
 dnl ***********************************************************************
 m4_define([gtk_required_version], [3.17.1])
 m4_define([glib_required_version], [2.45.1])
-m4_define([gtksourceview_required_version], [3.17.3])
+m4_define([gtksourceview_required_version], [3.17.8])
 m4_define([ggit_required_version], [0.23.5])
 m4_define([gjs_required_version], [1.42.0])
 m4_define([pygobject_required_version], [3.0.0])