user prefs shows redacted token symbols for empty fields

For the item on the screenshot below there is no value stored in Galaxy, the UI still shows the redacted symbols as if there was a token stored which is confusing to the user.

Ideally for missing optional values the field would just be empty.

chrome on macos on latest 24.2

No file or test is named; start by reproducing the user-preferences view in Chrome on macOS and tracing the field rendering for an optional value absent from Galaxy. Done means empty optional fields render without redacted token symbols, while stored values continue to display appropriately.

Written by the indexing model from the issue text.