Unable to close nb-datepicker pop-up by click-outside while nb-datepicker resides inside a nb-tabset

[Kolpak86]

Issue type

I'm submitting a ... (check one with "x")

• bug report
• feature request

Issue description

Current behavior:
Unable to close nb-datepicker pop-up by click-outside while nb-datepicker resides inside a nb-tabset. nb-datepicker that reside in the first tab that I outside is clicked/touched do work. nb-datepicker pop-up in all the other tabs no not closing when outside is clicked/touched. The nb-datepicker in the first tab that was clicked still work. This behaviour can be observed with any tab, as long as it is the first tab you click on after the app starts

Expected behavior:
That you can always close nb-datepicker pop-up in any tab by click-outside.

Steps to reproduce:
See current behaviour.

<nb-card size="medium" >
  <nb-card-header>
    Отчеты
  </nb-card-header>
  <nb-card-body>
    <nb-tabset (changeTab)="changeTab($event)" routeParam="tab">
      <nb-tab route="replaceable-reports" tabTitle="Replaceable reports">
        <replaceable-reports [cashBoxes]="cashBoxes"></replaceable-reports>
      </nb-tab>
      <nb-tab route="check-history" tabTitle="Check history">
        <check-history [cashBoxes]="cashBoxes"></check-history>
      </nb-tab>
    </nb-tabset>
  </nb-card-body>
</nb-card>

Other information:

npm, node, OS, Browser

<!--
Node, npm: `node --version` and `npm --version`
OS: Windows (7/8/10). Linux (incl. distribution). macOS (El Capitan? Sierra?)
Browser: Chrome/Safari/Firefox/etc?
-->

Angular, Nebular

[Kolpak86]

[nnixaa]

Fixed in #1316