avoid a null ref

OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs

@@ -512,7 +512,8 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                     if (((fi.MyFlags & (int)FriendRights.CanSeeOnline) != 0) && (fi.TheirFlags != -1))
                         friendList.Add(fi);
                 }
-
+                if(friendList.Count > 0)
+                {
                     Util.FireAndForget(
                         delegate
                         {
@@ -526,6 +527,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                     );
                 }
             }
+        }
 
         protected virtual void StatusNotify(List<FriendInfo> friendList, UUID userID, bool online)
         {
@@ -552,6 +554,8 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             // We do this regrouping so that we can efficiently send a single request rather than one for each
             // friend in what may be a very large friends list.
             PresenceInfo[] friendSessions = PresenceService.GetAgents(remoteFriendStringIds.ToArray());
+            if(friendSessions == null)
+                return;
 
             foreach (PresenceInfo friendSession in friendSessions)
             {