ungettext fix

lms/templates/library-block-author-preview-header.html

-<%! from django.utils.translation import ugettext as _ %>
+<%! from django.utils.translation import ungettext %>
 <div class="wrapper-xblock-message">
     <div class="xblock-message information">
         <p>
             <span class="message-text">
-                ${_('Showing all matching content eligible to be added into {display_name}. Each student will be assigned {max_count} component[s] drawn randomly from this list.').format(max_count=max_count, display_name=display_name)}
+                ${ungettext(
+                    'Showing all matching content eligible to be added into {display_name}. Each student will be assigned {max_count} component drawn randomly from this list.',
+                    'Showing all matching content eligible to be added into {display_name}. Each student will be assigned {max_count} components drawn randomly from this list.',
+                    max_count
+                ).format(max_count=max_count, display_name=display_name)}
             </span>
         </p>
     </div>

lms/templates/library-block-author-view.html

 <%!
-from django.utils.translation import ugettext as _
+from django.utils.translation import ungettext
 %>
 <div class="xblock-header-secondary">
-    <p>${_('This component will be replaced by {max_count} component[s] randomly chosen from the {num_children} matching components in {lib_names}.').format(mode=mode, max_count=max_count, num_children=num_children, lib_names=', '.join(library_names))}</p>
+    <p>${ungettext(
+        'This component will be replaced by {max_count} component randomly chosen from the {num_children} matching components in {lib_names}.',
+        'This component will be replaced by {max_count} components randomly chosen from the {num_children} matching components in {lib_names}.',
+        max_count
+    ).format(max_count=max_count, num_children=num_children, lib_names=', '.join(library_names))}</p>
 </div>