HashedWheelTimer resource leak

[Looveh]

When migrating many databases (1 SQL db, 8 Cassandra keyspaces, 1 Elasticsearch cluster) with many migrations (about 30 migrations per db) I get a report of resource leaking:

Apr 06, 2016 9:49:52 AM io.netty.util.ResourceLeakDetector reportLeak
SEVERE: LEAK: You are creating too many HashedWheelTimer instances.  
HashedWheelTimer is a shared resource that must be reused across the JVM,
so that only a few instances are created.