Omits null checking of treatment when removing next objectives; it was removed f…

…rom remove() but not for remove(context)

Change-Id: Id5acf7589e63dbf6f6c3dbd3253c5979fd5a478f

@@ -219,7 +219,6 @@ public final class DefaultNextObjective implements NextObjective {
             checkNotNull(appId, "Must supply an application id");
             checkNotNull(id, "id cannot be null");
             checkNotNull(type, "The type cannot be null");
-            checkArgument(!treatments.isEmpty(), "Must have at least one treatment");
 
             return new DefaultNextObjective(id, treatments, appId,
                                             context, type, Operation.REMOVE);