clear userAgent state on client shutdown, which fixes the issue

where you could only login once with a given id in standalone mode.

OpenSim/Region/Communications/OGS1/OGS1UserServices.cs

@@ -86,6 +86,11 @@ namespace OpenSim.Region.Communications.OGS1
             return null;
         }
 
+        public void clearUserAgent(LLUUID avatarID) 
+        {
+            // TODO: implement
+        }
+
         public UserProfileData SetupMasterUser(string firstName, string lastName)
         {
             return SetupMasterUser(firstName, lastName, "");

OpenSim/Region/Environment/Scenes/Scene.cs

@@ -674,7 +674,9 @@ namespace OpenSim.Region.Environment.Scenes
                 }
             }
             // TODO: Add the removal from physics ?
-
+            
+            // Remove client agent from profile, so new logins will work
+            commsManager.UserServer.clearUserAgent(agentID);
 
             return;
         }