add support for SetDesktopSize to java viewer

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4427 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/java/src/com/tigervnc/rfb/CMsgReaderV3.java b/java/src/com/tigervnc/rfb/CMsgReaderV3.java
index b865a6c..308d60d 100644
--- a/java/src/com/tigervnc/rfb/CMsgReaderV3.java
+++ b/java/src/com/tigervnc/rfb/CMsgReaderV3.java
@@ -62,7 +62,7 @@
       int y = is.readU16();
       int w = is.readU16();
       int h = is.readU16();
-      int encoding = is.readU32();
+      int encoding = is.readS32();
 
       switch (encoding) {
       case Encodings.pseudoEncodingDesktopSize: