http: re-word http error message

When we report an http error code, we say something like:

  error: The requested URL reported failure: 403 Forbidden while accessing http://example.com/repo.git

Everything between "error:" and "while" is written by curl,
and the resulting sentence is hard to read (especially
because there is no punctuation between curl's sentence and
the remainder of ours). Instead, let's re-order this to give
better flow:

  error: unable to access 'http://example.com/repo.git: The requested URL reported failure: 403 Forbidden

This is still annoyingly long, but at least reads more
clearly left to right.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http.c

@@ -943,7 +943,7 @@ cleanup:
 
 void http_error(const char *url)
 {
-	error("%s while accessing %s", curl_errorstr, url);
+	error("unable to access '%s': %s", url, curl_errorstr);
 }
 
 int http_fetch_ref(const char *base, struct ref *ref)