Merge branch 'http-empty-auth'

This topic branch fixes a rather serious regression with NTLM
authentication: when using "empty credentials", i.e. when inserting ":@"
into a URL (e.g. https://:@me.visualstudio.com/), we used to ask cURL to
use the login credentials. But a recent change broke that. Which this
branch fixes again.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: Git for Windows Build Agent

http.c

@@ -109,7 +109,7 @@ static int curl_save_cookies;
 struct credential http_auth = CREDENTIAL_INIT;
 static int http_proactive_auth;
 static const char *user_agent;
-static int curl_empty_auth;
+static int curl_empty_auth = 1;
 
 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;