haproxy_health: update help text

check_haproxy_health

@@ -40,6 +40,7 @@ It requires wget to handle the http request.
 Non OK values occur:
   UNKNOWN - if $HAPROXYcfgfile cannot be read
           - haproxy is not in http mode
+          - the url wasn't detected
           - the detected status url doesn't send a response
   ERROR - the detected status url did not respond with Http status 
           code 200

docs/20_Checks/check_haproxy_health.md

@@ -26,6 +26,7 @@ It requires wget to handle the http request.
 Non OK values occur:
   UNKNOWN - if /etc/haproxy/haproxy.cfg cannot be read
           - haproxy is not in http mode
+          - the url wasn't detected
           - the detected status url doesn't send a response
   ERROR - the detected status url did not respond with Http status 
           code 200