allow resetting and reapply config on broken clusters (#12554)

Bonus: remove kms_kes as sub-system, since its ENV only.
- also fixes a crash with etcd cluster without KMS
configured and also if KMS decryption is missing.

cmd/common-main.go

@@ -575,6 +575,7 @@ func handleCommonEnvVars() {
 		}
 		GlobalKMS = KMS
 	}
+
 	if tiers := env.Get("_MINIO_DEBUG_REMOTE_TIERS_IMMEDIATELY", ""); tiers != "" {
 		globalDebugRemoteTiersImmediately = strings.Split(tiers, ",")
 	}