subscribe to only those gossips that return via get_custody_column_subnet

beacon_chain/nimbus_beacon_node.nim

@@ -2047,9 +2047,13 @@ proc installMessageValidators(node: BeaconNode) =
           else:
             CUSTODY_REQUIREMENT.uint64
 
-        for it in 0'u64 ..< subnetCount:
+        let dc_subnets = get_custody_column_subnet(node.network.nodeId, subnetCount)
+        for it in 0'u64 ..< DATA_COLUMN_SIDECAR_SUBNET_COUNT:
           closureScope:  # Needed for inner `proc`; don't lift it out of loop.
             let subnet_id = it
+            if subnet_id notin dc_subnets.get:
+              discard
+            else:
               node.network.addValidator(
                 getDataColumnSidecarTopic(digest, subnet_id), proc (
                   dataColumnSidecar: DataColumnSidecar