-m ftp-archive fails due to hardcoded http:// protocol

[mulander]

In #433 protocol used for obtaining ftp archive release was changed from hard-coded ftp:// to http://. It appears that currently ftp-archive.freebsd.org no longer serves over http:// preventing any images from being downloaded.

Changing http:// to ftp:// in jail.sh solves the issue but might cause a regression of FTP protocol errors mentioned in #433.

# poudriere jail -c -j 104Ramd64 -v 10.4-RELEASE -a amd64 -m ftp-archive
[00:00:00] Creating 104Ramd64 fs at /usr/home/awolk/archives/B/build-artifacts/poudriere/jails/104Ramd64... done
[00:00:00] Using pre-distributed MANIFEST for FreeBSD 10.4-RELEASE amd64
[00:00:00] Fetching base for FreeBSD 10.4-RELEASE amd64             
fetch: http://ftp-archive.freebsd.org/pub/FreeBSD-Archive/old-releases/amd64/amd64/10.4-RELEASE/base.txz: Connection refused
fetch: http://ftp-archive.freebsd.org/pub/FreeBSD-Archive/old-releases/amd64/amd64/10.4-RELEASE/base.txz: Connection refused
[00:00:01] Error: Failed to fetch from http://ftp-archive.freebsd.org/pub/FreeBSD-Archive/old-releases/amd64/amd64/10.4-RELEASE/base.txz
[00:00:01] Error while creating jail, cleaning up.         
[00:00:01] Removing 104Ramd64 jail... done        
[00:00:01] Cleaning 104Ramd64 data... done  

[mulander]

I reported this upstream: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237579

[mulander]

Resolved by upstream restoring http:// support.