MAGETWO-92983: Duplicate required fields symbols in Category -> Display Settings Section

Author: svitja

app/code/Magento/Catalog/view/adminhtml/ui_component/category_form.xml

@@ -256,7 +256,6 @@
                 <item name="type" xsi:type="string">group</item>
                 <item name="config" xsi:type="array">
                     <item name="breakLine" xsi:type="boolean">true</item>
-                    <item name="required" xsi:type="boolean">true</item>
                 </item>
             </argument>
             <field name="available_sort_by" formElement="multiselect">
@@ -297,7 +296,6 @@
                 <item name="type" xsi:type="string">group</item>
                 <item name="config" xsi:type="array">
                     <item name="breakLine" xsi:type="boolean">true</item>
-                    <item name="required" xsi:type="boolean">true</item>
                 </item>
             </argument>
             <field name="default_sort_by" formElement="select">