This commit fixes osmo-gsm-tester_virtual, which currently fails because osmo-msc is unable to start:
DLSCCP NOTICE sccp_user.c:656 OsmoMSC-A-Iu: Requesting an SCCP simple client on ASP asp-clnt-OsmoMSC-A configured with 'sctp-role server' DLSCCP ERROR sccp_user.c:661 OsmoMSC-A-Iu: Requesting an SCCP simple client on ASP asp-clnt-OsmoMSC-A configured with 'sctp-role server' but no matching xUA server was configured!
