CU185-update.sh: Add drop hostile in & out logging entries if not already present

CU185-update.sh: Add drop hostile in & out logging entries if not already present

- This patch ensures that those people who updated to CU184 before the CU184-update.sh
   patch fix to add the logging entries was added will get their optionsfw settings file
   correctly updated with CU185
- This only adds the LOGDROPHOSTILEIN & LOGDROPHOSTILEOUT entries if they do noit already
   exist in the optionsfw settings file.

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