Duplicate prometheus metrics when testing/importing hermes, hermes2

[bziemons]

Motivation

Importing hermes and hermes2 at the same time now fails in testing, because the prometheus metrics are named the same and are initialized on module import.

The error is:

ValueError: Duplicated timeseries in CollectorRegistry: set(['rucio_daemons_hermes_reconnect_total', 'rucio_daemons_hermes_reconnect_created'])

which is caused on this line:

rucio/lib/rucio/daemons/hermes/hermes2.py

Line 73 in a4ea2cf

RECONNECT_COUNTER = Counter('rucio_daemons_hermes_reconnect', 'Counts Hermes reconnects to different ActiveMQ brokers', labelnames=('host',))

See the checks on PR #3947

Modification

Move initialization to the run Method