Schema registry: multiplied schemas into schema-registry-cluster.json

[francescolovecchio]

In the dashboard jmxexporter-prometheus-grafana/assets/grafana/provisioning/dashboards/schema-registry-cluster.json the number of schemas is multiplied by the n° of instances.

[ram-pi]

are you able to select the schema registry instance? if you select the instance you should see a reduced number of schemas