$NetBSD$

Portabilty fix.

--- configure.orig	2017-03-27 19:50:51.000000000 +0000
+++ configure
@@ -18269,7 +18269,7 @@ else
   have_dbus_launch=no
 fi
 fi
- if test "x$have_xvfb_run" == "xyes" -a "x$have_dbus_launch" == "xyes"; then
+ if test "x$have_xvfb_run" = "xyes" -a "x$have_dbus_launch" = "xyes"; then
   HAVE_HEADLESS_TESTS_TRUE=
   HAVE_HEADLESS_TESTS_FALSE='#'
 else
