fix optional unwrapping for new compiler version

'If value is nil and the type T is an Optional type at runtime, the return value will now be .some(nil) rather than nil. This behavior is consistent with the casting behavior when concrete types are used rather than generic types. (40916953)'

Sources/EasyDi.swift

@@ -365,9 +365,11 @@ open class Assembly: AssemblyInternal {
             result = singleton as! ObjectType
 
         // And trying to return object from graph
-        } else if let objectFromStack = context.objectGraphStorage[key] as? ObjectType, scope != .prototype {
+        } else if let objectFromStack = context.objectGraphStorage[key],
+            scope != .prototype,
+            let unwrappedObject = objectFromStack as? ObjectType {
 
-            result = objectFromStack
+            result = unwrappedObject
 
         } else {