get the manager for the correct trigger

currentTrigger in this context always refers to the first one on the list so it always returns the same manager. selectedTrigger refers to the correct object.
only go into key capture mode if the field is an instance of QSHotKeyField

The old test would prevent you from being able to edit the trigger name.
Merge pull request #1650 from quicksilver/triggerBugs

Trigger bugs