Add 1Password 4 transient type to the pasteboard ignore list

In 1Password 4 the Agile Bits guys added the `com.agilebits.onepassword` type and are requesting 3rd party apps ignore it (as a transient type)

For ref, here's what the Agile Guys said:

> we had to pull support for the @"org.nspasteboard.TransientType" type as it was causing problems with some apps. I had liked that type as it meant you didn't need to make any changes to QuickSilver but sadly it didn't pan out. We instead add a @"com.agilebits.onepassword" type so we won't affect (old, outdated, obsolete) apps.