Bug#837636: init script: remove seqfile logic

[Daniel Pocock]

Package: kamailio
Severity: normal
Version: 4.4.2-3

The init script contains logic for the RADIUS client seqfile:

https://anonscm.debian.org/cgit/pkg-voip/kamailio.git/tree/debian/kamailio.init#n60

seqfile was removed from the RADIUS client library some time ago:

https://github.com/radcli/radcli/issues/6

It was last present in FreeRADIUS client 1.1.6 but is not present in
1.1.7 or in radcli 1.2.0 or above.

Maybe this change needs to go upstream and also revise any other RADIUS
code or documentation for Kamailio