validate all proxies have been checked

[tatref]

Description

If the name of a proxy has a typo, it is possible to miss the correct proxy

Related Issue

Motivation and Context

How Has This Been Tested?

Current script:

./check_haproxy_stats.pl -p correct_proxy
Check haproxy OK - checked proxies: correct_proxy

./check_haproxy_stats.pl -p correct_proxy,proxy_with_typo
Check haproxy CRITICAL - Not all proxies checked for correct_proxy proxy_with_typo

This PR:

./check_haproxy_stats.pl -p correct_proxy
Check haproxy OK - checked proxies: correct_proxy

./check_haproxy_stats.pl -p correct_proxy,proxy_with_typo
Check haproxy OK - checked proxies: correct_proxy, proxy_with_typo

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Might be a breaking change, depending on how you implement monitoring

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.