Database replications on DR environments are not properly monitored

[dvalfre]

DR environments contain a db which is replicating from a main environment. As such, they should be monitored for replication status.

Turns out they are not.

Specifically, this code should be expanded so to recognize the presence of a DR setup and, in turn install the check for replication. An approach can be to set a variable to then evaluated here and here on the template which generates CollectD's configuration file.