fix missing profile banner bug

app/src/components/profile-header/profile-header.html

@@ -1,6 +1,6 @@
 <!-- Generated template for the ProfileHeaderComponent component -->
 <div>
-  <img src="{{ user.profile_banner_url }}" alt="{{ user.name }} - Banner" class="profile-banner">
+  <img src="{{ user.profile_banner_url }}" alt="{{ user.name }} - Banner" class="profile-banner" *ngIf="user.profile_banner_url">
   <img src="{{ user.profile_image_url_https }}" alt="{{ user.name }}" class="profile-picture">
   <div padding>
     <p class="profile-stats">{{ user.followers_count | friendlyNumber }} Followers | {{ user.friends_count | friendlyNumber }} Following</p>