fix 'http headers' param in test-validation

[ThomasLohner]

The param is actually called 'HTTP HEADERS' and not 'HOSTHEADER'.

see: https://mmonit.com/monit/documentation/monit.html

Syntax:

 PROTO(COL) HTTP
     [REQUEST "string"]
     [STATUS operator number]
     [CHECKSUM checksum]
     [HTTP HEADERS list of headers]
     [CONTENT {= | != } STRING]

[jonhattan]

Ouch. This changed in monit 5.9 - see changelog https://mmonit.com/monit/changes/

We need to identify the monit version in use, and generate the config in concordance.

[jonhattan]

Or, at least in this case, accept both params and add a comment indicating when HOSTHEADER was deprecated and HTTP HEADERS started being in force.

[ThomasLohner]

thx for the feedback. i'll fix.

[ThomasLohner]

I've added both Params and also provided a sample config for hiera in README.md

[jonhattan]

Merged. Thanks!