Description of problem:

With the fix of bz1930662 (backport of https://github.com/rear/rear/pull/2632) the file /usr/share/rear/output/PXE/default/820_copy_to_net.sh was removed because it duplicated the generic code in output/default/950_copy_result_files.sh and output/RSYNC/default/900_copy_result_files.sh. Its treatment of OUTPUT_URL was different though: output/RSYNC/default/900_copy_result_files.sh copies the output files (kernel+initrd) to BACKUP_URL and ignores OUTPUT_URL. In contrast, 820_copy_to_net.sh passes $OUTPUT_URL directly to rsync. As a result of its removal, the files are not at the place where the user expects them. This is a problem for DRLM, which configures ReaR this way: https://github.com/rear/rear/issues/2781

Without OUTPUT=PXE and with BACKUP=RSYNC, OUTPUT_URL is also ignored, but this has been always the case, so it is not a regression and I don't propose to fix it here (only in RHEL 9 with a more invasive change, bz2115958)

Version-Release number of selected component (if applicable):

2.4-19.el8

How reproducible:

mkrescue with appropriate settings is enough

Steps to Reproduce:
1. set BACKUP=RSYNC OUTPUT=PXE OUTPUT_URL=user@host:/path/rsync/output OUTPUT_URL=user@host:/path/rsync/backup
2. run rear mkrescue

Actual results:

The output files $(hostname -s).kernel and $(hostname -s).initrd.cgz are not found under /path/rsync/output on host (but they are under /path/rsync/backup)

Expected results:

The output files $(hostname -s).kernel and $(hostname -s).initrd.cgz are found under /path/rsync/output on host

Additional info:

OUTPUT_URL is used in an odd way here. Normally, ReaR uses its own rsync URL format (calling it "new style format"):

# rsync://[USER@]HOST[:PORT]/PATH    # using ssh
# rsync://[USER@]HOST[:PORT]::/PATH  # using rsync

but output/PXE/default/820_copy_to_net.sh passes the URL directly to rsync, which interprets it this way (ReaR calls it "old style format") :

# [USER@]HOST:PATH           # using ssh (no rsh)
#
# with rsync protocol PATH is a MODULE name defined in remote /etc/rsyncd.conf file
# [USER@]HOST::PATH          # using rsync
# rsync://[USER@]HOST[:PORT]/PATH    # using rsync (is not compatible with new style!!!)

This is different from the rest of ReaR, but should not be changed due to compatibility reasons: rsync://[USER@]HOST[:PORT]/PATH means using the rsync protocol (rsyncd) in the old style format, but ssh transport in the new style format. I plan to change it in RHEL 9, bz2115958