Form uses #value instead of #default_value

In links_weblink_form, the links_weblink_url element uses #value instead of #default_value. This results in the URL always being empty on submitting a new weblink. When used as a bookmarklet with nodeformpopup, changes to the URL have no effect. Changing #value to #default_value fixes both issues.
No *patch* provided for such a trivial change.