Timely added check for unsupported pixel format.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2104 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/win/rfb_win32/ScaledDIBSectionBuffer.cxx b/win/rfb_win32/ScaledDIBSectionBuffer.cxx
index 20d0f89..3b0f3f7 100644
--- a/win/rfb_win32/ScaledDIBSectionBuffer.cxx
+++ b/win/rfb_win32/ScaledDIBSectionBuffer.cxx
@@ -51,7 +51,7 @@
 void ScaledDIBSectionBuffer::setPF(const PixelFormat &pf_) {
   if (memcmp(&(ScaledPixelBuffer::pf), &pf_, sizeof(pf_)) == 0) return;
 
-  if (!pf_.trueColour) throw rfb::UnsupportedPixelFormatException();
+  if (pf_.depth != 24) throw rfb::UnsupportedPixelFormatException();
 
   pf = pf_;
   if (scaling) {