Bug 28148: Remove 'print' class from 'Print transfer slip' when transfer exists

Bug 28148: Remove 'print' class from 'Print transfer slip' when transfer exists

The 'print' class triggers JS to create the transfer and update a form

When a transfer exists we have no form and use 'openWin' to trigger the
print

Also, I remove a stray '1' in the template

To test:
1 - Set AutomaticItemReturn to "Don't"
2 - Check in an item from another branch
3 - Confirm the transfer
4 - Check it in again
5 - Click 'Print slip'
6 - Note error in console:
    Uncaught TypeError: this.form is null
7 - apply patch
8 - Repeat
9 - No error!

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 011ee862d375d1aceb694159cebe5b54d6e0f6b5)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>