Crowd REST client ignores http.nonProxyHosts

Crowd's REST client can take proxy configuration from the crowd.properties files:

http.proxy.host=
http.proxy.port=
http.proxy.username=
http.proxy.password=

These mirror the Java system properties:

http.proxyHost
http.proxyPort
http.proxyUser
http.proxyPassword

However, there is no equivalent of http.nonProxyHosts, the hosts that should be excluded from the proxy.

Rather than extending the Crowd configuration properties, configure the HTTP client so that it will fall back to using system properties when no http.proxy.host is set in the crowd.properties.