fix(user):register duplicate name

Author: caisi35

api/user/user.go

@@ -57,6 +57,14 @@ func AddUser(c *gin.Context) {
 Password: json.Password,
 }
 
+// duplicate name
+_, err = u.Where(u.Name.Eq(json.Name)).First()
+if !(err != nil && err.Error() == "record not found") {
+c.JSON(http.StatusConflict, gin.H{
+"message": "name already exists",
+})
+}
+
 err = u.Create(&user)
 
 if err != nil {