poolcounter: remove nrpe from role

nrpe is now in base see https://gerrit.wikimedia.org/r/#/c/124576/
This means since the host already has nrpe via base there is no need to include
it again

Change-Id: I6ab7f1afeb661e6c765be95b4d5435e47f2ba94d
Merge "poolcounter: remove nrpe from role" into production