Because of Hammer.js horizontal scrolling is not working inside a dialog

[tujlaky]

What version of ng-dialog are you using?
1.4.0

What version of AngularJS are you using?
1.6.6

What browsers are affected?

All versions of mobile safari.

Please provide either a JSFiddle, Plunkr example that replicates the issue

Please describe the issue

In this line hammerjs should be optional:
https://github.com/likeastore/ngDialog/blob/master/js/ngDialog.js#L721

What did you expect to happen?
All elements with overflow-x: scroll should be scrollable.

What actually happened?
Horizontal scrolling is not working.