update.sh: Remove ABUSECH_BOTNETC2 lists from users systems during update.

update.sh: Remove ABUSECH_BOTNETC2 lists from users systems during update.

- This removes ABUSECH_BOTNETC2 from users system during the update in the same way as
   done previously with ALIENVAULT and SPAMHAUS_EDROP.
- As next is still in CU192 I could not add these lines into the CU193 update.sh so I have
   added it to the CU192 update.sh
- If not appropriate then let me know and when the CU193 is created in next I will redo
   the patch and re-submit it.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>