dovecot - Nov 2019 - Lmtp proxy help assertion failed: (conn->remote_port != 0

I have this in my 20-lmtp.conf file and created passdb-file, this should 
be enough to route a message to svr1? The port 24 is reachable from the 
proxy.


bash-5.0# cat 20-lmtp.conf
lmtp_proxy = yes


protocol lmtp {
  # Space separated list of plugins to load (default is global 
mail_plugins).
  passdb {
  driver = passwd-file
  args = /etc/dovecot/special-passdb
  default_fields = proxy=y host=svr1
  }
}


bash-5.0# cat /etc/dovecot/special-passdb
test:password:1000:1000:(gecos):home:/bin/false:host=svr1