fix misspell (#1996)

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

modules/mailer/mailer.go

@@ -83,7 +83,7 @@ func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
 		case "Password:":
 			return []byte(a.password), nil
 		default:
-			return nil, fmt.Errorf("unknwon fromServer: %s", string(fromServer))
+			return nil, fmt.Errorf("unknown fromServer: %s", string(fromServer))
 		}
 	}
 	return nil, nil

routers/install.go

@@ -81,7 +81,7 @@ func Install(ctx *context.Context) {
 	form.RepoRootPath = setting.RepoRootPath
 	form.LFSRootPath = setting.LFS.ContentPath
 
-	// Note(unknwon): it's hard for Windows users change a running user,
+	// Note(unknown): it's hard for Windows users change a running user,
 	// 	so just use current one if config says default.
 	if setting.IsWindows && setting.RunUser == "git" {
 		form.RunUser = user.CurrentUsername()