[xcb/xsettings] Byte order byte is at address 0

Accoring to
    http://standards.freedesktop.org\
    	        /xsettings-spec/xsettings-spec-0.5.html
the byte order byte is address 0 (not 1).

Change-Id: I441084a7f24908dd8a504648bfc50ba2d486a586
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

src/plugins/platforms/xcb/qxcbxsettings.cpp

@@ -150,7 +150,7 @@ public:
     {
         if (xSettings.length() < 12)
             return;
-        char byteOrder = xSettings.at(1);
+        char byteOrder = xSettings.at(0);
         if (byteOrder != LSBFirst && byteOrder != MSBFirst) {
             qWarning("%s ByteOrder byte %d not 0 or 1", Q_FUNC_INFO , byteOrder);
             return;