Bump sockjs from 0.3.19 to 0.3.21 in /frontend#13

dependabot[bot] wants to merge 1 commit intomasterjaymagrob/sei-project-4:masterfrom

dependabot/npm_and_yarn/frontend/sockjs-0.3.21jaymagrob/sei-project-4:dependabot/npm_and_yarn/frontend/sockjs-0.3.21Copy head branch name to clipboard