try to fix "random config" tb

Internal libetonyek requires liblangtag. Build #227.

Change-Id: Ie4bace66f90d071db3d4f10bf2b45990b738f9dc
Reviewed-on: https://gerrit.libreoffice.org/34483Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

configure.ac

@@ -11606,6 +11606,9 @@ if test "$enable_liblangtag" = "yes" -o \
     fi
     AC_DEFINE(ENABLE_LIBLANGTAG)
 else
+    if test "x$SYSTEM_ETONYEK" = "x"; then
+            AC_MSG_ERROR([internal libetonyek requires liblangtag])
+    fi
     AC_MSG_RESULT([no])
 fi
 AC_SUBST(ENABLE_LIBLANGTAG)