When opening ngx-form-error page this raise an jasvscript error.

ISSUES CLOSED: #43

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NationalBankBelgium/ngx-form-errors/blob/master/CONTRIBUTING.md#-commit-message-guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

Bugfix issue when opening ngx-form-error page

[X] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Raise an javascript error and do not render the page

Issue Number: #43

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[X] No

Other information