Backport: Fixed Erroneous HEXTILE test

The HEXTILE test which tested for a background tile followed
by an empty tile was only wide enough to actually test for one
tile, thus not actually testing the functionality.  It now actually
uses two tiles, thus actually testing the functionality.

(cherry picked from commit 4865278d)

tests/test.rfb.js

@@ -1318,7 +1318,7 @@ describe('Remote Frame Buffer Protocol Client', function() {
                         client._display._fb_width = 8;
                         client._display._viewportLoc.w = 8;
 
-                        var info = [{ x: 0, y: 0, width: 8, height: 4, encoding: 0x05 }];
+                        var info = [{ x: 0, y: 0, width: 32, height: 4, encoding: 0x05 }];
 
                         var rect = [];