Commit 7affc2f7 removed var initialization

That commit accidentally removed the initialization of the "start"
variable giving undefined results for the host extraction from the
url input.

src/transports/ssh.c

@@ -215,6 +215,7 @@ static int git_ssh_extract_url_parts(
 		*username = git__substrdup(url, at - url);
 		GITERR_CHECK_ALLOC(*username);
 	} else {
+		start = url;
 		*username = NULL;
 	}