make check fails without --enable-lua: check_SCRIPTS not gated on if LUA

[thegushi]

Summary

miltertest — the test harness used by every test in check_SCRIPTS — is only compiled when Lua is enabled (miltertest/Makefile.am):

if LUA
bin_PROGRAMS = miltertest
...
endif

All test scripts invoke ../../miltertest/miltertest. If the tree is configured without --enable-lua, miltertest is never built, and make check fails for every test with a "command not found" error rather than a clean skip.

Specific cases

Beyond the global dependency, two tests additionally require opendkim to have been built with Lua support (they use SetupPolicyScript in their configs), but are listed unconditionally in check_SCRIPTS:

• t-sign-rs-lua — uses t-sign-rs-lua.lua-setup
• t-lua-verify-tests — Lua-only test harness

For comparison, feature-optional tests that are already correctly gated: t-lua-rbl (if LIVE_TESTS + if RBL), t-verify-ss-rep (if REPUTE), t-sign-ss-replace (if REPLACE_RULES), t-sign-atps / t-verify-ss-atps (if ATPS), t-sign-ss-conditional (if CONDITIONAL).

Fix

Wrap the entire check_SCRIPTS assignment in opendkim/tests/Makefile.am inside if LUA:

if LUA
check_SCRIPTS = t-sign-ss t-sign-rs ...
...
endif

This makes a build without --enable-lua produce a clean make check with zero tests run rather than a cascade of failures.