Fixes for metrics bugs GH-1001 and GH-1022

[zarembsky]

• Have you followed the guidelines in CONTRIBUTING.md?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you added an explanation of what your changes do?
• Does your submission pass tests?
• Did you lint your code prior to submission?

[zarembsky]

Does not allow to change master to develop

[lidel]

Worth including v6 version as well:

-		if (requestHost === 'localhost' || requestHost === '127.0.0.1') {
+		if (requestHost === 'localhost' || requestHost === '127.0.0.1' || requestHost === '[::1]') {

[christophertino]

Good catch, i'll add it