chore(deps): bump jsrsasign from 8.0.16 to 8.0.20 in /example

Bumps [jsrsasign](https://github.com/kjur/jsrsasign) from 8.0.16 to 8.0.20.
- [Release notes](https://github.com/kjur/jsrsasign/releases)
- [Changelog](https://github.com/kjur/jsrsasign/blob/master/ChangeLog.txt)
- [Commits](kjur/jsrsasign@8.0.16...8.0.20)

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