Bug 25032: Chomp stringified exception

Bug 25032: Chomp stringified exception

If we catch a Koha::Exception-derived exception, the log is put in a
single line. If the code 'dies' then a newline character is appended to
the string. This patch chomps it so it displays in a single line.

To test:
1. Tweak Koha::REST::V1::Cities::list in the try block so it dies before
   render
2. Restart plack and try the original test plan
=> FAIL: Notice two lines are logged
3. Apply this patch
4. Repeat 2
=> SUCCESS: Only one line in the logs
5. Verify rendering a Koha::Exception works as well:
   Koha::Exceptions::Exception->throw("Nada!");

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>