BF: filter.d/dropbear

Add PAM failures which is in dropbear-2013.60 in srv-authpam.c

Patch
http://www.unchartedbackwaters.co.uk/files/dropbear/dropbear-0.52.patch
obviously has exit with lower case e so adjust regex for both.

svr-authpasswd.c in 2013.60 (at bottom) for second regex ends after the
IP so the regex was altered.

.*\s* can be compressed to .*
Merge pull request #408 from grooverdan/dropbear

BF: filter.d/dropbear