Temporary workaround for #3211
This reverts the effect of https://github.com/marijnh/CodeMirror/commit/4a745fe6680d104ff4c4347617a5964dcb01c46b,
which seems to cause #3211 and doesn't seem to be fixing any issues we're currently having.
Merge pull request #3212 from adobe/nj/issue-3211

Temporary workaround for #3211