upgrade json schema from ^0.3.0 to 0.4.0

[thomasbricchi]

I got his using npm audit fix --force

json-schema <0.4.0 Severity: moderate json-schema is vulnerable to Prototype Pollution - https://github.com/advisories/GHSA-896r-f27r-55mw No fix available node_modules/json-schema ng-openapi-gen * Depends on vulnerable versions of json-schema node_modules/ng-openapi-gen

2 moderate severity vulnerabilities

resoursces:

• https://sca.analysiscenter.veracode.com/vulnerability-database/security/prototype-pollution/javascript/sid-32973
• https://github.com/advisories/GHSA-896r-f27r-55mw

[luisfpg]

It was already updated to 0.4.0 in 0.20.0