Default "automatically unlock" checkbox to false
The GCR prompt used to unlock keyrings and other secure objects has a checkbox for automatically unlocking the object when the user logs in. Previously, this checkbox was checked by default if the object in question had the CKA_GNOME_TRANSIENT attribute set. This linkage frankly makes no sense; the change can be traced back to a nine-year-old commit (084ce5e0) which appears to have mistakenly altered code that used CKA_GNOME_TRANSIENT to determine the nature of the choice into code that used CKA_GNOME_TRANSIENT to set the default value of the choice.
Defaulting this checkbox to true, which was the practical effect of using CKA_GNOME_TRANSIENT in this way, has obvious drawbacks for security, as the reporter of #7 and the various reporters in bugs linked from there have attested.
Removing this linkage is a small change, but it results in a larger amount of code being no longer needed, which this commit cleans up.