fix FRC breaking again for iOS 8

Sources/FetchedResultsControllerDelegate.swift

@@ -185,6 +185,10 @@ internal final class FetchedResultsControllerDelegate: NSObject, NSFetchedResult
                 )
                 return
             }
+            guard #available(iOS 9.0, tvOS 9.0, watchOS 9.0, *) else {
+                
+                return
+            }
             self.handler?.controller(
                 controller,
                 didChangeObject: anObject,