style: format code with Go fmt and Gofumpt

This commit fixes the style issues introduced in cddfd5f according to the output
from Go fmt and Gofumpt.

Details: https://github.com/gogs/gogs/pull/8105

internal/database/issue_label.go

@@ -52,7 +52,7 @@ func GetLabelTemplateFile(name string) ([][2]string, error) {
 // Label represents a label of repository for issues.
 type Label struct {
 	ID              int64
-	RepoID          int64  `gorm:"index"`
+	RepoID          int64 `gorm:"index"`
 	Name            string
 	Color           string `gorm:"type:varchar(7)"`
 	NumIssues       int