[mod_magnet] reset config cache for uri components
[mod_magnet] reset config cache for uri components

reset config cache after modifications to uri components
  lighty.r.req_attr["uri.scheme"]
  lighty.r.req_attr["uri.authority"]
  lighty.r.req_attr["uri.path"]
  lighty.r.req_attr["uri.query"]

Changes might affect subsequent modules when those modules patch config,
but does not affect the core config options which have already been
processed.

If lighttpd config needs to be reprocessed after making changes, then
return lighty.RESTART_REQUEST from lua script to tell lighttpd to
restart the request, including reprocessing the core config options.

lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4