fix documentation typos in the WS compression enable property name

ScalaWS and JavaWS docs incorrectly specified the property to turn on WS compression as `ws.compressionEnable`. I noticed this property had no effect and it actually needs to be `ws.compressionEnabled`. 

Would love to see this change make it into the 2.3.x/2.4.x branches as it would probably save some developer frustration. Not sure about the process for making this happen but let me know if/how I can help. Thanks!