www/{nginx-module-lua,nginx-module-lua-stream}: Fix Lua on freenginx

Both modules call ngx_ssl_client_hello_callback(), guarded only by
nginx_version > 1029001. freenginx reports 1030001 but has no such
function, so load_module failed with an undefined symbol. Skip the
call on freenginx, as the modules already do on nginx before 1.29.2.

ngx.req.start_time() returned r->start_time / 1000.0. freenginx takes
start_time from ngx_current_msec, which is CLOCK_MONOTONIC and not the
Unix epoch, so ngx.now() - ngx.req.start_time() silently returned
garbage. Derive the epoch value from the current time and the elapsed
milliseconds.

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