Revert "Changed url on webview sample"

This reverts commit 92ae25ec3c240217f5584372abadaabedd3952df.

There doesn't seem to be any good reason to use wiki.wxwidgets.org
instead of the main site.

samples/webview/webview.cpp

@@ -66,7 +66,7 @@ class WebApp : public wxApp
 {
 public:
     WebApp() :
-        m_url("http://wiki.wxwidgets.org")
+        m_url("http://www.wxwidgets.org")
     {
     }