message: App: Add implements OnDestroy to UserImageDirective
diff: -import {Directive, HostBinding, Input, OnInit, SimpleChange} from '@angular/core';
  +import {Directive, HostBinding, Input, OnInit, OnDestroy, SimpleChange} from '@angular/core';
  import {DomSanitizer, SafeStyle} from '@angular/platform-browser';
  import {IUser} from '../../../../../../shared/models/IUser';
  import {BackendService} from '../services/backend.service';
  @@ -6,7 +6,7 @@ import {BackendService} from '../services/backend.service';
  const md5 = require('blueimp-md5');
  @Directive({selector: '[user-image]'})
  -export class UserImageDirective implements OnInit {
  +export class UserImageDirective implements OnInit, OnDestroy {
  @Input('user-image') user: IUser;
  @Input('size') size = '100%';
  