fix: Editing an asset with no shelf/category crash

internal/ui/assets/astdialogs/edit.go

@@ -374,9 +374,17 @@ func (d *AssetEditDialog) initData() {
 
 		// Location category
 		d.assetShelfField.SetOptions(shelfOptions, nil)
-		d.assetShelfField.SetCurrentOption(findOption(shelfOptions, d.asset.ShelfLocation.Name))
+		if d.asset.ShelfLocation != nil {
+			d.assetShelfField.SetCurrentOption(findOption(shelfOptions, d.asset.ShelfLocation.Name))
+		} else {
+			d.assetShelfField.SetCurrentOption(0)
+		}
 		d.assetCategoryField.SetOptions(categoryOptions, nil)
-		d.assetCategoryField.SetCurrentOption(findOption(categoryOptions, d.asset.Category.Name))
+		if d.asset.Category != nil {
+			d.assetCategoryField.SetCurrentOption(findOption(categoryOptions, d.asset.Category.Name))
+		} else {
+			d.assetCategoryField.SetCurrentOption(0)
+		}
 
 		// Comments category
 		d.assetCommentsArea.SetText("", true)