REST Health service error

[maniac777]

Describe the bug
In current version of application GIT main and in previous release health reset service is not responding.

To Reproduce
Steps to reproduce the behavior:

1. Enable public health service.
2. Try to call it with following headers:

GET /pwm/public/rest/health HTTP/1.1
User-Agent: check_http/v2.1.1 (monitoring-plugins 2.1.1)
Connection: close
Host: __DOMAIN__
Accept: */*

HTTP/1.1 200
Date: Tue, 21 Dec 2021 08:07:02 GMT
Server: PWM
Vary: Accept-Encoding
Content-Language: en
X-PWM-Noise: NrYK7GhqY6mqmG4prVj
X-Content-Type-Options: nosniff
X-XSS-Protection: 1
X-PWM-Instance: 37F1484C92C74383
X-Frame-Options: DENY
X-PWM-Amb: j00s j0ur d4ddy
Cache-Control: no-cache, no-store, must-revalidate, proxy-revalidate
Content-Type: application/json;charset=UTF-8
Content-Length: 74
X-Robots-Tag: noindex, noarchive, nosnippet
Connection: close
**** CONTENT ****
{"error":true,"errorCode":7000,"errorMessage":"Error_RestInvocationError"}

Expected behavior
I expect to receive json object with health status as in previous releases.

[maniac777]

I've debugged out a problem a bit with colegue. He found out that in server/src/main/java/password/pwm/ws/server/rest/RestHealthServer.java there are two methods:

1. @RestMethodHandler( method = HttpMethod.GET, produces = HttpContentType.plain )
   private RestResultBean doPwmHealthPlainGet( final RestRequest restRequest )
2. @RestMethodHandler( method = HttpMethod.GET, consumes = HttpContentType.json, produces = HttpContentType.json )
   private RestResultBean doPwmHealthJsonGet( final RestRequest restRequest )

This was a hint. In first method any error is catched. So this was a hint that i did not hit the first method. Setting request header "Content-Type: text/plain" clould be enaugh to make it working.

I believe that this should be fixed to give some more helpfull error message, documented or fixed in the way that content-type is not required in GET request.

[msoltyspl]

For the record, this is still an issue in version 2.0.4 (forcing content-type to application/json with e.g. curl's -H workarounds the issue as well)