make magic string an const

Author: 6543

models/issues/pull.go

@@ -29,6 +29,8 @@ import (
 
 var ErrMustCollaborator = util.NewPermissionDeniedErrorf("user must be a collaborator")
 
+const reviewedBy = "Reviewed-by: "
+
 // ErrPullRequestNotExist represents a "PullRequestNotExist" kind of error.
 type ErrPullRequestNotExist struct {
 	ID         int64
@@ -392,7 +394,7 @@ func (pr *PullRequest) getReviewedByLines(ctx context.Context, writer io.Writer)
 		} else if review.Reviewer == nil {
 			continue
 		}
-		if _, err := writer.Write([]byte("Reviewed-by: ")); err != nil {
+		if _, err := writer.Write([]byte(reviewedBy)); err != nil {
 			return err
 		}
 		if _, err := writer.Write([]byte(review.Reviewer.NewGitSig().String())); err != nil {