Readme: Refer to code.qt.io, not gitorious

Gitorious was sold and will close down shop soon.

Change-Id: Ic27da9a45a42f2dc7ba2badf3f3b10a6ec058e8d
Reviewed-by: Liang Qi <liang.qi@theqtcompany.com>

README.md

@@ -13,7 +13,7 @@ It is implemented as a Qt add-on module, that can easily be embedded into existi
 Qt 5.x
 
 ### Build And Usage
-Checkout the source code from gitorious
+Checkout the source code from code.qt.io
 Go into the source directory and execute:
 
     qmake