Description of problem:
The latest rsnapshot release treats rsync exit codes 23 and 24 a simple warning, with *no* output unless "verbose" > 3. While exit code 24 (file vanished) can be considered as a simple warning, exit code 23 (I/O error) should *not* be considered as such; rather, it should be very clearly indicated in the output at verbose level 2 or 3.

Please see PR#179 (https://github.com/rsnapshot/rsnapshot/pull/179) for more details.

Version-Release number of selected component (if applicable):
1.4.2

How reproducible:
Create a rsnapshot configuration backing up a non-existant directory, run rsnapshot and see how it fails (with exit code 2) with *no* warning on the command line.

Steps to Reproduce:
1. create a rsnapshot configuration backing up a non-existant directory;
2. run rsnashot;
3. the backup fails with nothing printed on the command line.

Actual results:
No error/warning shown.

Expected results:
IO Error should generate a very clear warning/error/report on the command line.

Additional info:
See PR179: https://github.com/rsnapshot/rsnapshot/pull/179