[gthumb] Build against either webkit2gtk-3.0 or webkit2gtk-4.0

[Paolo Bacchilega <paobac src gnome org>]

commit 4c64cb990fc1e32e269571b34065d7aa8d92c79e
Author: Dominique Leuenberger <dimstar opensuse org>
Date:   Fri Aug 15 16:47:27 2014 +0200

    Build against either webkit2gtk-3.0 or webkit2gtk-4.0
    
    The API changes were minor and none affected gthumb.

 configure.ac |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 6f9f03e..da246f9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -508,10 +508,14 @@ AC_ARG_ENABLE([webkit2],
 
 if test x$enable_webkit2 = xyes ; then
        PKG_CHECK_MODULES(WEBKIT2,
-                         [webkit2gtk-3.0 >= $WEBKIT2_REQUIRED],
+                         [webkit2gtk-4.0 >= $WEBKIT2_REQUIRED],
                          [AC_DEFINE(HAVE_WEBKIT2, 1, [Have webkit2gtk])
                           enable_webkit2=yes],
-                         [enable_webkit2=no])
+                         [PKG_CHECK_MODULES(WEBKIT2,
+                                            [webkit2gtk-3.0 >= $WEBKIT2_REQUIRED],
+                                            [AC_DEFINE(HAVE_WEBKIT2, 1, [Have webkit2gtk])
+                                             enable_webkit2=yes],
+                                            [enable_webkit2=no])])
 fi
 AC_SUBST(WEBKIT2_CFLAGS)
 AC_SUBST(WEBKIT2_LIBS)