[dnsdist] Exceed-Warning after adding some more listeners

[Tom]

Hi list

Using dnsdist 1.5.2. After adding some more udp/tcp-listeners on 
differnt IP addresses with addLocal, addTLSLocal and addDOHLocal, I got 
the following warning:
Adding a new TCP client thread would exceed the vector capacity (10/10), 
skipping

Is there a limit of 10 listening-sockets? Can this be increased? Or some 
other hints for this?

Many thanks.
Kind regards,
Tom