freeswitch-stable: add SIGKILL to init script

freeswitch-stable: add SIGKILL to init script

Sometimes freeswitch doesn't exit after receiving the SIGTERM signal.
This can be reproduced by sending SIGTERM to a freeswitch instance which
is initializing (which can take quite some time).

Instead of just giving up and exiting - leaving a hung freeswitch
process on the system - this commit adds some lines to the init script
that send SIGKILL to freeswitch in case the attempt to terminate it with
SIGTERM fails.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>