[rygel] build: Check for gtk-doc

[Jens Georg <jensgeorg src gnome org>]

commit 0d73566a1ca6dcf34097651cde783124e35b7e2a
Author: Jens Georg <mail jensge org>
Date:   Fri Jul 27 22:16:09 2012 +0200

    build: Check for gtk-doc

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 78071a4..3dd7aec 100644
--- a/configure.ac
+++ b/configure.ac
@@ -210,6 +210,7 @@ AS_IF([test "x$enable_valadoc" != "xno"], [
     AS_IF([test -x "$VALADOC"], [
       found_valadoc=yes
       AC_SUBST(VALADOC)
+      PKG_CHECK_MODULES([GTKDOCK],[gtk-doc >= 1.0])
     ], [
       AS_IF([test "x$enable_valadoc" == "xyes"], AC_MSG_ERROR([Unable to find valadoc]))
     ])