Allow Flickr uploads in uploadwizard role

Set $wgAllowCopyUploads = true to enable "uploads by url", in
many places in MediaWiki.

Change $wgGroupPermissions to all users to upload by url.
Note: on Wikimedia Commons, this right is restricted only
to some users.

Change-Id: Ib127ff2fa6f20cabbf1d3e79c2a191d5f0c99d81