Updated the default class name

• Updated:
- the default class name

app/javascript/gabsocial/components/pill_item.js

@@ -46,7 +46,7 @@ class PillItem extends React.PureComponent {
     const active = isActive || (to === location.pathname && !location.search) || isCurrent
 
     const containerClasses = CX({
-      _: 1,
+      d: 1,
       noUnderline: 1,
       text: 1,
       aiCenter: 1,
@@ -63,7 +63,7 @@ class PillItem extends React.PureComponent {
     })
 
     const textParentClasses = CX({
-      _: 1,
+      d: 1,
       h100PC: 1,
       aiCenter: 1,
       jcCenter: 1,