Fix Jetty issue with "Blocking message pending 10000"

Author: Zomis

games-server/src/main/kotlin/net/zomis/games/server2/ws/WebClient.kt

@@ -7,11 +7,14 @@ import net.zomis.games.server2.Client
 internal class WebClient(val conn: WsSession): Client() {
 
     private val logger = KLoggers.logger(this)
+    private val lock = Any()
 
     override fun sendData(data: String) {
-        if (conn.isOpen) {
-            logger.info("Send to $this: $data")
-            conn.send(data)
+        synchronized(lock) {
+            if (conn.isOpen) {
+                logger.info("Send to $this: $data")
+                conn.send(data)
+            }
         }
     }