Initial min/max values need to be changed once to get active

[philippotto]

Context

When opening a dataset link, the pre-set min/max values of a color layer may end up not being used for rendering until the min/max slider was changed once.

Expected Behavior

The displayed min/max values in the sidebar should be used for rendering without any user interaction.

Current Behavior

The user needs to change min/max for the initial values to take effect.

Steps to Reproduce the bug

• Cannot reproduce the bug anymore / needs deeper investigation.

1. open https://webknossos.org/datasets/scalable_minds/l4dense_motta_et_al_types/view#2867,4160,1770,0,0.563 in incognito tab
2. change min/max slider for color layer a tiny bit --> contrast changes dramatically (which means that the values weren't properly used before).

Your Environment for bug

• Browser name and version: Chrome 90
• Operating System and version: Ubuntu 20.04
• Version of WebKnossos (Release or Commit): f471130

[MichaelBuessemeyer]

How to reproduce locally:

• Go to the settings of a dataset and then to the "View Configurations"-tab.
• There choose a (e.g. uint8) color layer and set min to 100 and max to 150.
• Then make the dataset publically available under the "Sharing & Permissions"-tab, copy the sharing link and save the settings.
• Then open the dataset with the public/sharing link in a private browser tab.
• The rendered color layer should (with the bug) render data like the histogram slider is at [0,255].