Bug 23181: Unable to use payment library in ACCOUNT_PAYMENT or ACCOUNT_WRITEOFF notices

Do to a simple semantic typo, the branches key will always be null for the tables key of the parameters for GetPreparedLetter.

Test Plan:
0) Activate UseEmailReceipts
1) Attempt to use [% branch.branchname %] in the ACCOUNT_PAYMENT notice
2) Note it produces no output
3) Apply this patch
4) Make another payment
5) You should now see the branche's name!

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Also requires UseEmailReceipts to be activated.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Koha/Account.pm

@@ -281,7 +281,7 @@ sub pay {
                 lang    => $patron->lang,
                 tables => {
                     borrowers       => $self->{patron_id},
-                    branches        => $self->{library_id},
+                    branches        => $library_id,
                 },
                 substitute => {
                     credit => $payment,