salt_minion monitoring - only CRIT if > 2

salt_minion process check, do not go
CRITICAL if there are (temporarily) 2 processes
running. still warn about it though, warning
does not spam IRC but can be seen in web ui

Change-Id: Ia198d1b385ad9171a98f355e812237f4d658dd60
Merge "salt_minion monitoring - only CRIT if > 2" into production