Code Formats, Nits & Unused Func/Var deletions (#15286)

* _ to unused func options

* rm useless brakets

* rm trifial non used models functions

* rm dead code

* rm dead global vars

* fix routers/api/v1/repo/issue.go

* dont overload import module

routers/repo/issue.go

@@ -52,8 +52,6 @@ const (
 )
 
 var (
-	// ErrTooManyFiles upload too many files
-	ErrTooManyFiles = errors.New("Maximum number of files to upload exceeded")
 	// IssueTemplateCandidates issue templates
 	IssueTemplateCandidates = []string{
 		"ISSUE_TEMPLATE.md",