fix compilation issues on my system

src/com/jpexs/decompiler/flash/SWF.java

@@ -1533,6 +1533,11 @@ public final class SWF implements TreeItem, Timelined {
                 return fframes.size() > pos;
             }
 
+            @Override
+            public void remove() {
+                throw new UnsupportedOperationException();
+            }
+
             @Override
             public BufferedImage next() {
                 if (!hasNext()) {