Fix zero created time bug on commit api (#17546)

Fix #17543

modules/convert/git_commit.go

@@ -147,8 +147,9 @@ func ToCommit(repo *models.Repository, commit *git.Commit, userCache map[string]
 
 	return &api.Commit{
 		CommitMeta: &api.CommitMeta{
-			URL: repo.APIURL() + "/git/commits/" + commit.ID.String(),
-			SHA: commit.ID.String(),
+			URL:     repo.APIURL() + "/git/commits/" + commit.ID.String(),
+			SHA:     commit.ID.String(),
+			Created: commit.Committer.When,
 		},
 		HTMLURL: repo.HTMLURL() + "/commit/" + commit.ID.String(),
 		RepoCommit: &api.RepoCommit{
@@ -169,8 +170,9 @@ func ToCommit(repo *models.Repository, commit *git.Commit, userCache map[string]
 			},
 			Message: commit.Message(),
 			Tree: &api.CommitMeta{
-				URL: repo.APIURL() + "/git/trees/" + commit.ID.String(),
-				SHA: commit.ID.String(),
+				URL:     repo.APIURL() + "/git/trees/" + commit.ID.String(),
+				SHA:     commit.ID.String(),
+				Created: commit.Committer.When,
 			},
 		},
 		Author:    apiAuthor,