Improve issues.LoadProject (#22982)

issues.LoadProject() is no use
change `issues.loadProject(ctx)` to issues.LoadProject(ctx)

Author: yp05327

Diff for: models/issues/issue.go

@@ -347,7 +347,7 @@ func (issue *Issue) LoadAttributes(ctx context.Context) (err error) {
 		return
 	}
 
-	if err = issue.loadProject(ctx); err != nil {
+	if err = issue.LoadProject(ctx); err != nil {
 		return
 	}
 

Diff for: models/issues/issue_project.go

@@ -13,11 +13,7 @@ import (
 )
 
 // LoadProject load the project the issue was assigned to
-func (issue *Issue) LoadProject() (err error) {
-	return issue.loadProject(db.DefaultContext)
-}
-
-func (issue *Issue) loadProject(ctx context.Context) (err error) {
+func (issue *Issue) LoadProject(ctx context.Context) (err error) {
 	if issue.Project == nil {
 		var p project_model.Project
 		if _, err = db.GetEngine(ctx).Table("project").