Add const for 'scope-' prefix.

Author: telackey

modules/indexer/issues/db/options.go

@@ -35,7 +35,7 @@ func ToDBOptions(ctx context.Context, options *internal.SearchOptions) (*issue_m
 	case internal.SortByDeadlineAsc:
 		sortType = "nearduedate"
 	default:
-		if strings.HasPrefix(string(options.SortBy), "scope-") {
+		if strings.HasPrefix(string(options.SortBy), issue_model.ScopeSortPrefix) {
 			sortType = string(options.SortBy)
 		} else {
 			sortType = "newest"

modules/indexer/issues/dboptions.go

@@ -102,7 +102,7 @@ func ToSearchOptions(keyword string, opts *issues_model.IssuesOptions) *SearchOp
 		// Unsupported sort type for search
 		fallthrough
 	default:
-		if strings.HasPrefix(opts.SortType, "scope-") {
+		if strings.HasPrefix(opts.SortType, issues_model.ScopeSortPrefix) {
 			searchOpt.SortBy = internal.SortBy(opts.SortType)
 		} else {
 			searchOpt.SortBy = SortByUpdatedDesc