Make sure maskSize bytes are skipped

If the CompressedQuickTime opcode has a mask then this wasn't processed properly. See for example P30946BDC.pict.

imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReader.java

@@ -1593,6 +1593,7 @@ public final class PICTImageReader extends ImageReaderBase {
         // ...and more
         int accuracy = pStream.readInt();
         int maskSize = pStream.readInt();
+        pStream.skipBytes(maskSize);
 
         if (DEBUG) {
             System.out.print("matteSize: " + matteSize);