[gnome-builder] build: fix webkit check

[Marc-Antoine Perennou <marcop src gnome org>]

commit 5039e61ed735ac377c0f1b3de5afc2432c945c0f
Author: Marc-Antoine Perennou <Marc-Antoine Perennou com>
Date:   Tue Jun 7 00:50:17 2016 +0200

    build: fix webkit check
    
    Signed-off-by: Marc-Antoine Perennou <Marc-Antoine Perennou com>

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0343479..26e9425 100644
--- a/configure.ac
+++ b/configure.ac
@@ -235,7 +235,7 @@ AS_IF([test "$enable_webkit" != no],[
                          [have_webkit=yes],
                          [have_webkit=no])
 
-       AS_IF([test "$enable_webkit" = "yes" && "$have_webkit" = "no"],[
+       AS_IF([test "$enable_webkit" = "yes" && test "$have_webkit" = "no"],[
               AC_MSG_ERROR([--enable-webkit requires webkit2gtk-4.0 >= webkit_required_version])
        ])