10l: really fix preferredEncoding set from outside

TODO

@@ -5,7 +5,6 @@ VisualNaCro testing
 test IRIX -overlay (x11vnc)
 java vncviewer doesn't do colour cursors?
 MinGW32 doesn't do fcntl on sockets; use setsockopt instead...
-if preferredEncoding is set outside of libvncserver, don't override it.
 make libvncclient threadsafe (static zlib buffer -> rfbClient*)
 make corre work again (libvncclient or libvncserver?)
 implement zrle in libvncclient

libvncserver/rfbserver.c

@@ -283,7 +283,7 @@ rfbNewTCPOrUDPClient(rfbScreen,sock,isUDP)
       cl->reverseConnection = FALSE;
       cl->readyForSetColourMapEntries = FALSE;
       cl->useCopyRect = FALSE;
-      cl->preferredEncoding = rfbEncodingRaw;
+      cl->preferredEncoding = -1;
       cl->correMaxWidth = 48;
       cl->correMaxHeight = 48;
 #ifdef LIBVNCSERVER_HAVE_LIBZ
@@ -1331,6 +1331,7 @@ rfbSendFramebufferUpdate(cl, givenUpdateRegion)
                                       + w * (cl->format.bitsPerPixel / 8) * h);
 
         switch (cl->preferredEncoding) {
+	case -1:
         case rfbEncodingRaw:
             if (!rfbSendRectEncodingRaw(cl, x, y, w, h))
 	        goto updateFailed;