s2e_config: RemoteMemory: convert python config to lua

This commit contains a small bugfix: if the "listen" address, of the
RemoteMemory is specified in the main python config file (i.e.
avatar-samples/*.py) then this address is used.

Signed-off-by: Lucian Cojocar <cojocar@gmail.com>
Signed-off-by: Jonas Zaddach <zaddach@eurecom.fr>