[core] disable stat_cache FAM if FAM conn closed
[core] disable stat_cache FAM if FAM conn closed

x-ref:
  "Lighttpd Stopping suddenly, no apparent reason on the logfile"
  https://redmine.lighttpd.net/boards/2/topics/8702

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