Add prefix to update-responses xml files

When publishing 14.5 we found that the update-responses URL from 14.5 release was not working.

It appears that having files named 14.5-14.5.1+13.5.16-linux-x86_64.xml and 14.5.1+13.5.16-linux-x86_64.xml in the directory is causing the ^14.5/ rewrite rule to stop working.

After checking the apache errors log, it seems the issue is caused by mod_negotiation:

20:25 < LeLutin> boklm: I see lots of errors like this: AH00687: Negotiation: discovered file(s) matching request:
                 /srv/static.torproject.org/mirrors/aus1.t
20:25 < LeLutin> orproject.org/cur/torbrowser/update_3/release/windows-x86_64/14.5 (None could be negotiated).

https://httpd.apache.org/docs/2.4/mod/mod_negotiation.html

To avoid issues when mod_negotiation is enabled, we can add some prefix to the update-responses xml files.