configure: Check for gnutls_mac_get_key_size() instead of gnutls_transport_set_errno().
diff --git a/configure.ac b/configure.ac
index 6bbb4b9..784107e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -938,7 +938,7 @@
     ac_gnutls_cflags="`$PKG_CONFIG --cflags gnutls 2>/dev/null`"
     CPPFLAGS="$CPPFLAGS $ac_gnutls_cflags"
     AC_CHECK_HEADER(gnutls/gnutls.h,
-        [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gnutls/gnutls.h>]], [[typeof(gnutls_transport_set_errno) *pfunc;]])],
+        [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gnutls/gnutls.h>]], [[typeof(gnutls_mac_get_key_size) *pfunc;]])],
             [WINE_CHECK_SONAME(gnutls,gnutls_global_init,
                 [AC_SUBST(GNUTLSINCL,"$ac_gnutls_cflags")],,[$ac_gnutls_libs])])])
     CPPFLAGS="$ac_save_CPPFLAGS"