[devhelp] build: add missing AX_REQUIRE_DEFINED

[Sébastien Wilmet <swilmet src gnome org>]

commit 8f7adaa9e3b29682041574ee59b43c9808647d27
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Wed Mar 1 13:49:39 2017 +0100

    build: add missing AX_REQUIRE_DEFINED
    
    For every macro used that is not part of Autotools, there should be a
    AX_REQUIRE_DEFINED.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f999808..cd4cd5a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,6 +45,7 @@ APPSTREAM_XML
 AX_REQUIRE_DEFINED([GLIB_GSETTINGS])
 GLIB_GSETTINGS
 
+AX_REQUIRE_DEFINED([GOBJECT_INTROSPECTION_CHECK])
 GOBJECT_INTROSPECTION_CHECK([1.30.0])
 
 AX_REQUIRE_DEFINED([AX_COMPILER_FLAGS])