[Snyk] Security upgrade express from 4.18.2 to 4.21.2

[kisuka]

Snyk has created this PR to fix 1 vulnerabilities in the npm dependencies of this project.

Snyk changed the following file(s):

• package.json
• package-lock.json

Vulnerabilities that will be fixed with an upgrade:

	Issue	Score
	Regular Expression Denial of Service (ReDoS) SNYK-JS-PATHTOREGEXP-8482416	738

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[Heresor]

Makes PR #119 obsolete. Dependency updates.