mcd_config_drift metric is not cleared properly.

Description:
When a config drift happens mcd_config_drift metric is updated, but if we delete the MCD pod running on the node where the config drift happened the metric is cleared.

Reproduce
1. Force a config drift in a node
The mcd_config_drift metric will report the drift properly
2. Remove the MCD pod that is running in the node where the drift happened

Current behaviour:
The metric is set to "0" after the MCD pod is removed.

Expected behaviour:
The metric should only be set to "0" when the config drift stops happening.