Avoid overlong regex line in javascript.

The regex line in this javascript was > 256 characters, which triggers the following warning from debian's "lintian" source-checking tool:

https://lintian.debian.org/tags/source-is-missing.html
https://lintian.debian.org/tags/source-contains-prebuilt-javascript-object.html

This offers no functional change, but avoids some needless warnings going forward.