Bug 18449: Rename misleading button when renewing

Bug 18449: Rename misleading button when renewing

If you hit the renewal limit on the renewal tab, the message gives you a
message like:

"Windows 8 / ( 50610018249545 ) has been renewed the maximum number of
times by Johnny Test ( 12345678 )"

And has a button that reads:

"Ignore and continue"

This button is misleading, as it may be interpreted as "ignore the limit
and continue to renew the item".

Signed-off-by: Dominic Pichette <dominic@inlibro.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>