The ReverseProxySetupMonitor seems to be broken.

I get the following log output if I use one of the following

• BASE=administrativeMonitor/hudson.diagnosis.ReverseProxySetupMonitor
  curl -iL -e http://your.reverse.proxy/jenkins/manage \
              http://your.reverse.proxy/jenkins/${BASE}/test
  

• the reverse proxy monitor internally uses an Redirect to

  http://your.reverse.proxy/jenkins/administrativeMonitor/hudson.diagnosis.ReverseProxySetupMonitor/testForReverseProxySetup/http%3A%2F%2Fyour.reverse.proxy%2Fjenkins%2Fmanage/
  

  If I use this URL directly with curl I get the same error.

 WARNING	h.d.ReverseProxySetupMonitor#getTestForReverseProxySetup: http://your.reverse.proxy/jenkins/manage vs. http:

If I manipulate the url at the end of the URL the log message changes.

I assume an issue in the process of decoding the parameter of ReverseProxySetupMonitor#getTestForReverseProxySetup.

Maybe this is a regression in stapler.