Handle unreachable errors better

lib/msf/core/exploit_driver.rb

@@ -253,7 +253,7 @@ protected
 					exploit.fail_reason = Msf::Exploit::Failure::NoAccess
 				when /connection reset/i
 					exploit.fail_reason = Msf::Exploit::Failure::Disconnected
-				when /connection timed out|SSL_connect/i
+				when /connection timed out|SSL_connect|unreachable/i
 					exploit.fail_reason = Msf::Exploit::Failure::Unreachable
 				when /unable.*target/i
 					exploit.fail_reason = Msf::Exploit::Failure::NoTarget