Avoid logging "failed to delete" error messages

- Only tries to delete an item if it exists in the Keychain. This avoids unnecessary error messages in the console, because this isn't actually an error.
Merge pull request #16 from fcy/patch-1

Avoid logging "failed to delete" error messages
Removed leftover "beta" in file headings
Merge branch 'master' of https://github.com/nicklockwood/FXKeychain
Updated to version 1.5.1
Merge pull request #6 from nicklockwood/master

同步到最新