Bug 36676: SIP2 drops connection on unknown patron id in fee paid message

Bug 36676: SIP2 drops connection on unknown patron id in fee paid message

When sending a fee paid message to SIP2 with an unknown patron id it will respond with an empty response followed by dropping the connection to a client.

Test plan:
a) perl /usr/share/koha/bin/sip_cli_emulator.pl -a 127.0.0.1 -p 6001 -su term1 -sp term1   -l CPL --patron 2352900100046 -m fee_paid --fee-type FT --fee-amount 0.01
Output:
Trying 'fee_paid'
SEND: 3720240423    124447FT00USDBV0.01|AO|AA2352900100046|ACterm1|
Use of uninitialized value $data in concatenation (.) or string at /usr/share/koha/bin/sip_cli_emulator.pl line 355, <GEN0> chunk 1.
READ:

b) apply patch
c) perl /usr/share/koha/bin/sip_cli_emulator.pl -a 127.0.0.1 -p 6001 -su term1 -sp term1   -l CPL --patron 2352900100046 -m fee_paid --fee-type FT --fee-amount 0.01
Output:
Trying 'fee_paid'
SEND: 3720240423    125602FT00USDBV0.01|AO|AA2352900100046|ACterm1|
READ: 38N20240423    125602AO|AA2352900100046|AFInvalid patron barcode.|

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>