Bug 17144: Fix variable scope issues in edi_account.pl

Bug 17144: Fix variable scope issues in edi_account.pl

To reproduce:
- In Staff client, go to Administration > EDI accounts
- Click "+ New account"
Result: Internal Server Error
Plack error log says:
Can't call method "param" on an undefined value at /home/marc/koha/admin/edi_accounts.pl line 157

To test:
-Apply patch
- Add an EDI account
- Edit an EDI account
- Delete an EDI account

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Katrin Fischer  <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>