change KSecAttrAccessible in KeychainItemWrapper after saving value

Question

In my previous version of the application (iPhone) I kept value (Password) in the keychain in the following code:

KeychainItemWrapper * keychain = [[KeychainItemWrapper alloc] initWithIdentifier:@"KeychainTest" 
                                                                     accessGroup:nil];

[keychain setObject: kSecAttrAccessibleWhenUnlocked forKey:(id)kSecAttrAccessible];

[keychain setObject: @ "MySuperSecretPassword" forKey:(id)kSecValueData];

[keychain release];

and get the value in folwing code:

KeychainItemWrapper *keychain = [[KeychainItemWrapper alloc] initWithIdentifier:@"KeychainTest" 
                                                                    accessGroup:nil];

[keychain setObject: kSecAttrAccessibleWhenUnlocked forKey:(id)kSecAttrAccessible];

NSString *key = [keychain objectForKey:(id)kSecValueData];

because sometimes my application run in the background i found a bug I can not get my value from the Keychain.

I fixed the bug by change the value of kSecAttrAccessible from kSecAttrAccessibleWhenUnlocked to kSecAttrAccessibleAlways.

KeychainItemWrapper * keychain = [[KeychainItemWrapper alloc] initWithIdentifier:@"KeychainTest" 
                                                                 accessGroup:nil];
[keychain setObject:kSecAttrAccessibleAlways forKey:kSecAttrAccessible];

[keychain setObject: @"MySuperSecretPassword" forKey: kSecValueData];
 
[keychain release];

and:

KeychainItemWrapper *keychain = [[KeychainItemWrapper alloc] initWithIdentifier:@"KeychainTest" 
                                                                    accessGroup:nil];

    [keychain setObject: kSecAttrAccessibleAlways forKey:(id)kSecAttrAccessible];

    NSString *key = [keychain objectForKey:(id)kSecValueData];

My question is : if this change will also help to users That save the value in previous versions.

my bug is very difficult to restore it, so I ask the question. right now I could not recover thre bug after this change.

Thanks