title: Subscribing on ReplaySubject doesn't work
body: <p>I have this on my authentication </p>
  
  <pre><code>public currentUser: ReplaySubject&lt;User&gt; = new ReplaySubject&lt;User&gt;(1);
  </code></pre>
  
  <p>when user login i use </p>
  
  <pre><code>  public setCurrentUser(user: User) {
      this.currentUser.next(user);
    }
  </code></pre>
  
  <p>to set the user object.</p>
  
  <p>The problem exists on <code>CanActivateGuard</code>, I think it not see the <code>currentUser</code> somehow </p>
  
  <p>this is the code</p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import { CanActivate, Router } from '@angular/router';
  import { AuthService } from './auth.service';
  
  import {User} from '../models/user';
  
  
  @Injectable()
  export class CanActivateGuard implements CanActivate {
    private logged: boolean = false;
  
    constructor(
      private router: Router,
      public _auth: AuthService
    ) {
      console.log('CanActivateGuard');
  
      this._auth.currentUser.subscribe(
        (user) =&gt; {
          this.logged = user.logged;
          console.log('user');
          console.log(user);
        },
        (error) =&gt; {
          console.log(error);
        }
      );
    }
  
    public canActivate() {
  
      if ( !this.logged ) {
         this.router.navigate( [ 'login' ] );
      }
      console.log(this.logged);
      return this.logged;
    }
  }
  </code></pre>
  
  <p>It never reach <code>this.logged = user.logged;</code> I think it see this._auth.currentUser as empty</p>
  
  <p>This is the link of the whole project: <a href="https://github.com/MoustafaElkady/You360-Web-Client/tree/master/src/app" rel="nofollow noreferrer">https://github.com/MoustafaElkady/You360-Web-Client/tree/master/src/app</a></p>