url-http.el: calling the callback function for proxy connections

[Klaus Straubinger <KSNetz@UseNet.ArcorNews.DE>]

The function url-http-activate-callback calls the callback function
after completing the URL retrieval. If the connection had been through
a proxy, the variable url-current-object contains only the proxy
reference.

All callback functions that want to evaluate or display which URL had
been retrieved are not working properly when using the variable
url-current-object or the function url-view-url that also uses
url-current-object.

My proposal is to do

  (let ((url-current-object url-http-target-url))

around

  (apply url-callback-function url-callback-arguments)

within the function url-http-activate-callback as already done in the
function url-http-handle-cookies.

This would, for example, make HTTP-EQUIV redirects handled by the W3
package work even for proxy connections.

-- 
Klaus Straubinger