Second Daemon is not used by stratum
**Describe the bug**
We have two fullnodes per coin configured. When I shut down the primary fullnode Miningcore stops working. It does not switch to the second fullnode. We have encountered this behaviour with ERGO.

**To Reproduce**
Set up two ERGO Fullnodes, configure them as deamons in MC Stratum. Shut the first daemon from the configuration down.

**Expected behavior**
Miningcore should automatically switch over to second daemon.

