Follow-up of #1664940: [Policy, patch] Decide on JSHint configuration and part of #1415788: [Meta] javascript spring clean-up
Fix any warnings or errors the tool finds.
Check manually that the fixes did not break any functionalities
Create patch and upload for the testbot.
core/modules/editor/js/editor.js: line 72, col 17, Expected '===' and instead saw '=='.