Change handling of the SYSTEMIP constant to be more sane.

This will now choose the first network interface IP address, or the loopback
interface if no external interfaces are found. It will log the IP address
used as [NETWORK]: Using x.x.x.x for SYSTEMIP.

OpenSim/Region/Application/OpenSim.cs

@@ -190,6 +190,8 @@ namespace OpenSim
 
             PrintFileToConsole("startuplogo.txt");
 
+            m_log.InfoFormat("[NETWORK]: Using {0} as SYSTEMIP", Util.GetLocalHost().ToString());
+
             // For now, start at the 'root' level by default
             if (m_sceneManager.Scenes.Count == 1) // If there is only one region, select it
                 ChangeSelectedRegion("region",