"Show confidence intervals" toggle appears for divergent tree

[eharkins]

Current Behavior
"Show confidence intervals" toggle in the sidebar appears when moving from a "radial" to a "rectangular" tree when the tree "Branch Length" control is set to "divergence."

Expected behavior
"Show confidence intervals" toggle in the sidebar should not appear for any combination of tree control settings that includes "Branch Length" control being set to "divergence" (unless there were confidence intervals for the divergence values - unsure if this is supported).

How to reproduce

1. Go to https://nextstrain.org/dengue/denv1
2. Change "Branch Length" to "divergence"
3. Change "Layout" from "rectangular" to "radial"
4. Change "Layout" back to "rectangular",
5. "Show confidence intervals" toggle appears again even though it's still on "divergence"; toggling it does nothing in this state.

It may not have any adverse affects in terms of breaking the state of the toggle upon switching back to the rectangular tree but it seems like a bug in the state described above.

Possible solution
Adding a clause to this expression that checks state.distanceMeasure

Working on it now.

Your environment: if browsing Nextstrain online

• Operating system: macOS High Sierra 10.13.4
• Browser: Chrome 80.0.3987.149 (Official Build) (64-bit)