Fix 1.6.4 legacy support

In 1.6.4, the correct format for a ping was to send '0xFE 0x01', however Bungee requires an additional byte (0xFA). 

1.6.4 clients will not show out of date warnings for 1.7.2 versions of Bungee without this fix, they will only show "Communication Error". This fix will also allow server list sites that do not support the new 1.7.2 protocol to query bungee, as well as sites like MineCanary.