Fix close modal icon position

client/src/app/+videos/+video-edit/shared/video-caption-add-modal.component.html

@@ -3,6 +3,7 @@
 
     <div class="modal-header">
       <h4 i18n class="modal-title">Add caption</h4>
+
       <button class="border-0 p-0" title="Close this modal" i18n-title (click)="hide()">
         <my-global-icon iconName="cross"></my-global-icon>
       </button>

client/src/sass/bootstrap.scss

@@ -144,6 +144,8 @@ body {
     margin-bottom: 5px;
 
     .modal-title {
+      @include margin-right(auto);
+
       font-size: 20px;
       font-weight: $font-semibold;
     }