[gom] build: Make gdk-pixbuf an optional dependency

[Patrick Welche <pwelche src gnome org>]

commit 34184c1e292d8d0c269d477ef9669a7da0127422
Author: Patrick Welche <prlw1 cam ac uk>
Date:   Mon Dec 8 19:45:24 2014 +0000

    build: Make gdk-pixbuf an optional dependency
    
    gdk-pixbuf is only needed for the unit tests. Instead of bailing
    if gdk-pixbuf is not found, don't build the tests, i.e., behave as
    if --disable-glibtest had been specified.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=741219

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1a0ce64..a45f4e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -57,7 +57,6 @@ dnl **************************************************************************
 PKG_CHECK_MODULES(GIO,     [gio-2.0 >= 2.36])
 PKG_CHECK_MODULES(GOBJECT, [gobject-2.0 >= 2.36])
 PKG_CHECK_MODULES(SQLITE3, [sqlite3 >= 3.7])
-PKG_CHECK_MODULES(PIXBUF, [gdk-pixbuf-2.0])
 
 
 dnl **************************************************************************
@@ -126,6 +125,7 @@ dnl Unit Tests
 dnl **************************************************************************
 AC_PATH_PROG([GTESTER], [gtester])
 AC_PATH_PROG([GTESTER_REPORT], [gtester-report])
+PKG_CHECK_MODULES(PIXBUF, [gdk-pixbuf-2.0], [], [enable_glibtest=no])
 AM_CONDITIONAL(ENABLE_GLIB_TEST, test "x$enable_glibtest" = "xyes")