Modified the client_alive_interval default to suggested value from cis benchmark.

While this cookbook isn't specific (and shouldn't be specific) to CIS Benchmarks, it's helpful as a
baseline to set the default behaviors to the recommended value. Folks can override to 600 if needed.

Signed-off-by: Jennifer Davis <[email protected]>

Author: iennae

attributes/default.rb

@@ -82,7 +82,7 @@
   server['dh_build_primes']          = false
   server['dh_build_primes_size']     = 4096
   server['host_key_files']           = nil
-  server['client_alive_interval']    = 600     # 10min
+  server['client_alive_interval']    = 300     # 5min
   server['client_alive_count']       = 3       # ~> 3 x interval
   server['allow_root_with_key']      = false
   server['allow_tcp_forwarding']     = false