Avoid calling wait(0)

Calling wait(0) results in waiting without a timeout, which is
unintended.

Refs #6009 comment <https://github.com/Genymobile/scrcpy/pull/6009#issuecomment-2935930294>

server/src/main/java/com/genymobile/scrcpy/control/Controller.java

@@ -699,7 +699,9 @@ public class Controller implements AsyncProcessor, VirtualDisplayListener {
                 if (timeout < 0) {
                     return null;
                 }
+                if (timeout > 0) {
                     displayDataAvailable.wait(timeout);
+                }
                 data = displayData.get();
             }