Add possible extra parameter to webview creation wizard

git-svn-id: http://csipsimple.googlecode.com/svn/trunk/CSipSimple@2125 9f815046-5998-e9c0-b7e2-ac03a23edfa4
Fixes issue 2236. Thanks to Paul for the fix.

git-svn-id: http://csipsimple.googlecode.com/svn/trunk/CSipSimple@2126 9f815046-5998-e9c0-b7e2-ac03a23edfa4