Make window clamping more robust for invalid values

app/src/main/java/io/xpipe/app/core/AppWindowHelper.java

@@ -269,6 +269,11 @@ public class AppWindowHelper {
             changed = true;
         }
 
+        // This should not happen but on weird Linux systems nothing is impossible
+        if (w < 0 || h < 0) {
+            return Optional.empty();
+        }
+
         return changed ? Optional.of(new Rectangle2D(x, y, w, h)) : Optional.empty();
     }