Bug 18789: (QA follow-up) Use first_valid_email_address on Tranfers to receive page

Bug 18789: (QA follow-up) Use first_valid_email_address on Tranfers to receive page

For consistancy with waitng reserves

Test plan:
1) Have a hold for patron which need to be transfered, inititate
transfer and go to target library
2) Go to Circulation -> transfers to receive page and you should see any
first valid email for tha patron in column "On hold for"

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>