www/freenginx-devel: update njs 0.9.1 -> 0.9.3 (+)

While I'm here, adopt the start-up script for jail usage.

Bump PORTREVISION.

<ChangeLog>

Changes with njs 0.9.3 07 Oct 2025

nginx modules:

*) Bugfix: fixed heap-use-after-free while module loading.

*) Bugfix: fixed heap-use-after-free in js_set handler used

in log phase. The issue was introduced in 04f6dfb (0.9.2).

Changes with njs 0.9.2 23 Sep 2025

nginx modules:

*) Feature: added HTTP keepalive support for ngx.fetch() API.

*) Improvement: added configure time check when js_import is

not defined.

*) Bugfix: fixed merging of js_path directives.

*) Bugfix: fixed building when http_ssl and stream_ssl

unavailable.

Core:

*) Change: increased the default stack size to 160k for njs VM.

*) Feature: added njs.on('exit') API for qjs engine.

*) Improvement: optimized memory consumption while streaming

in qjs.

*) Bugfix: fixed building qjs engine with clang 19.

*) Bugfix: fixed building with GCC 15 and -O3.

</ChangeLog>