Rename the 2 outbound interface keys that were introduced by Deuce in the big

IPv6 commit of 2015:
"OutgoingV4" is now "OutboundInterface" and
"OutgoingV6" is now "OutboundV6Interface" (which is not yet used)

src/sbbs3/sbbs_ini.c

@@ -47,8 +47,8 @@ static const char*  strAutoStart="AutoStart";
 static const char*  strCtrlDirectory="CtrlDirectory";
 static const char*  strTempDirectory="TempDirectory";
 static const char*	strOptions="Options";
-static const char*	strOutgoing4="OutgoingV4";
-static const char*	strOutgoing6="OutgoingV6";
+static const char*	strOutgoing4="OutboundInterface";
+static const char*	strOutgoing6="OutboundV6Interface";
 static const char*	strInterfaces="Interface";
 static const char*	strPort="Port";
 static const char*	strMaxClients="MaxClients";