Bug 36249: Fix generic_confirm op

Bug 36249: Fix generic_confirm op

Test plan, k-t-d:

1) Install FreeForm, enable ILL module, run:
bash <(curl -s https://raw.githubusercontent.com/ammopt/koha-ill-dev/master/start-ill-dev.sh)
2) You'll have to switch the FreeForm branch to the one compatible with this work, i.e.:
cd /kohadevbox/koha/Koha/Illbackends/FreeForm
git checkout b_36243
3) Restart plack:
koha-plack --restart kohadev
4) Start by adding an e-mail address to the patron of category "Inter-library Loan", visit:
<staff_url>/cgi-bin/koha/members/memberentry.pl?op=edit_form&destination=circ&borrowernumber=16
5) Add an e-mail address to "Primary e-mail"
6) Create a new FreeForm request, visit:
<staff_url>/cgi-bin/koha/ill/ill-requests.pl?method=create&backend=FreeForm
7) Set 'type' enter '42' in cardnumber and pick a library. Click 'Create'.
8) Click "Place request with partners"
9) Pick a partner library (will be the same patron from step 4)
10) Click "Send email". Notice the CSRF error.
11) Apply patch and restart plack
koha-plack --restart kohadev
12) Repeat 8-10. Notice error no longer shows.
13) Notice the request's status is now 'Requested from partners'

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>