Remove unused `tap` import

apps/chat-room/src/app/app.component.ts

@@ -1,7 +1,7 @@
 import { Component } from '@angular/core';
 import { MessagesService } from './messages.service';
 import { Observable } from 'rxjs';
-import { map, tap } from 'rxjs/operators';
+import { map } from 'rxjs/operators';
 import { Message } from '@chat-room/api-interfaces';
 
 @Component({