Fix: support Apache Listen ip:port format in healthcheck

[Lyric-c]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description:

The current implementation assumes that the Apache Listen directive
contains only a port number (e.g. "Listen 80").

However, Apache also supports the "ip:port" format, such as:
Listen 127.0.0.1:3000

In this case, the existing parsing logic extracts "127.0.0.1:3000"
and passes it directly to netcat as the port argument, which results in:

nc: port number invalid

This PR updates the parsing logic to extract only the port portion
from the Listen directive, ensuring compatibility with both formats.

It also ensures only the first Listen directive is used to avoid
passing multiple ports to netcat.

Benefits of this PR and context:

• Fixes incorrect healthcheck behavior when using "Listen ip:port"
• Maintains full backward compatibility with existing configurations
• Prevents netcat invocation errors due to invalid port format
• Adds basic safety by selecting only the first Listen directive

This change improves robustness without altering existing behavior
for standard configurations.

This issue may occur when users run the container with host networking
and bind Apache explicitly to localhost (127.0.0.1).

How Has This Been Tested?

Tested in a Docker environment using linuxserver/smokeping:2.9.0.

Test cases:

1. Default configuration:
   Listen 80
   → Healthcheck works as expected

2. Custom port:
   Listen 3000
   → Healthcheck works as expected

3. IP + port configuration:
   Listen 127.0.0.1:3000
   → Previously failed with:
   nc: port number invalid
   → After patch:
   Healthcheck succeeds correctly

4. Multiple Listen directives:
   Listen 127.0.0.1:3000
   Listen 0.0.0.0:8080
   → Healthcheck uses the first Listen directive (3000)
   → Container starts and healthcheck succeeds

Also verified that the container starts normally and Apache becomes available
without impacting other functionality.

Source / References:

Apache Listen directive documentation:
https://httpd.apache.org/docs/current/mod/mpm_common.html#listen

Netcat usage reference:
nc -z

This issue was identified by inspecting the generated s6 service run script:
/var/run/s6/db/servicedirs/svc-apache/run

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[LinuxServer-CI]

I am a bot, here are the test results for this PR:
https://ci-tests.linuxserver.io/lspipepr/smokeping/2.9.0-r0-pkg-4956dfbb-dev-36f193e7e95c3cc1a34f298b383124bb401106bf-pr-212/index.html
https://ci-tests.linuxserver.io/lspipepr/smokeping/2.9.0-r0-pkg-4956dfbb-dev-36f193e7e95c3cc1a34f298b383124bb401106bf-pr-212/shellcheck-result.xml

Tag	Passed
amd64-2.9.0-r0-pkg-4956dfbb-dev-36f193e7e95c3cc1a34f298b383124bb401106bf-pr-212	✅
arm64v8-2.9.0-r0-pkg-4956dfbb-dev-36f193e7e95c3cc1a34f298b383124bb401106bf-pr-212	❌

[LinuxServer-CI]

I am a bot, here are the test results for this PR:
https://ci-tests.linuxserver.io/lspipepr/smokeping/2.9.0-r0-pkg-964505a4-dev-7b7404724029d74d93567553d517e4cc2643b581-pr-212/index.html
https://ci-tests.linuxserver.io/lspipepr/smokeping/2.9.0-r0-pkg-964505a4-dev-7b7404724029d74d93567553d517e4cc2643b581-pr-212/shellcheck-result.xml

Tag	Passed
amd64-2.9.0-r0-pkg-964505a4-dev-7b7404724029d74d93567553d517e4cc2643b581-pr-212	✅
arm64v8-2.9.0-r0-pkg-964505a4-dev-7b7404724029d74d93567553d517e4cc2643b581-pr-212	❌