webUI tests do not run with latest docker-selenium 3.141.59-palladium

[phil-davis]

When using the release tag https://github.com/SeleniumHQ/docker-selenium/releases/tag/3.141.59-palladium the webUI tests timeout trying to access the login screen.

Others are also having problems, see SeleniumHQ/docker-selenium#919
Raised own issue SeleniumHQ/docker-selenium#922

Example CI run is #35441 https://drone.owncloud.com/owncloud/core/18073/681

To do when the chrome 75 + chromedriver issues are resolved:

• go back to using selenium/standalone-chrome-debug:latest in drone
• revert "temporary" docs change Document selenium chrome testing version docs#1677

[phil-davis]

For now, we are reverting drone CI to use the previous selenium/standalone-chrome-debug:3.141.59-oxygen which has chrome 74.
master #35442
stable10 #35443

[individual-it]

phoenix owncloud/web#1260

[phil-davis]

This is likely related to https://bugs.chromium.org/p/chromedriver/issues/detail?id=2536
"Make standards mode (goog:chromeOptions.w3c:true) the default"