apply to costumes, not sounds

src/components/asset-panel/selector.jsx

@@ -29,7 +29,7 @@ const Selector = props => {
                         name={item.name}
                         selected={index === selectedItemIndex}
                         onClick={onItemClick}
-                        onDeleteButtonClick={items.length > 1 ? onDeleteClick : null}
+                        onDeleteButtonClick={onDeleteClick}
                     />
                 ))}
             </Box>
@@ -57,7 +57,7 @@ Selector.propTypes = {
         url: PropTypes.string,
         name: PropTypes.string.isRequired
     })),
-    onDeleteClick: PropTypes.func.isRequired,
+    onDeleteClick: PropTypes.func,
     onItemClick: PropTypes.func.isRequired,
     selectedItemIndex: PropTypes.number.isRequired
 };

src/containers/costume-tab.jsx

@@ -109,7 +109,7 @@ class CostumeTab extends React.Component {
                 }]}
                 items={target.costumes || []}
                 selectedItemIndex={this.state.selectedCostumeIndex}
-                onDeleteClick={this.handleDeleteCostume}
+                onDeleteClick={target.costumes.length > 1 ? this.handleDeleteCostume : null}
                 onItemClick={this.handleSelectCostume}
             >
                 {target.costumes ?