use alberti's alias (db)

This bypasses the "User root" configuration in my SSH config and is
more future-proof.

tsa/howto/build_and_upload_debs.mdwn

@@ -137,10 +137,10 @@ you to upload built packages to the server, provided you have the
 required accesses:
 
     [tpo-admin]
-    fqdn = alberti.torproject.org
+    fqdn = db.torproject.org
     incoming = /srv/db.torproject.org/ftp-archive/archive/pool/tpo-all/
     method = sftp
-    post_upload_command = ssh alberti.torproject.org make -C /srv/db.torproject.org/ftp-archive
+    post_upload_command = ssh db.torproject.org make -C /srv/db.torproject.org/ftp-archive
 
 This might require fixing some permissions. Do a `chmod g+w` on the
 broken directories if this happens. See also [ticket 34371](https://trac.torproject.org/projects/tor/ticket/34371) for