[gtk+/gtk-3-22] configure: Add missing quotes to unbreak an AS_IF

[Daniel Boles <dboles src gnome org>]

commit 7b68c234b1ef1a114eea784aed00193fcb0576f5
Author: Hannes Müller <h c f mueller gmx de>
Date:   Mon Aug 14 19:17:17 2017 +0200

    configure: Add missing quotes to unbreak an AS_IF
    
    Without quoting, the comma in AC_MSG_ERROR was wrongly interpreted as
    separating the if and else paths.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=786287

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 6b87415..25b25da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -456,7 +456,7 @@ if test "$enable_wayland_backend" = "yes"; then
   WAYLAND_PACKAGES="$WAYLAND_DEPENDENCIES"
   AC_PATH_PROG([WAYLAND_SCANNER],[wayland-scanner],[no])
   AS_IF([test "x$WAYLAND_SCANNER" = "xno"],
-    AC_MSG_ERROR([Could not find wayland-scanner in your PATH, required for parsing wayland extension 
protocols]))
+    [AC_MSG_ERROR([Could not find wayland-scanner in your PATH, required for parsing wayland extension 
protocols])])
   AC_SUBST([WAYLAND_SCANNER])
 
   AM_CONDITIONAL(USE_WAYLAND, true)