pastes: don't 404 when user does not exist

Signed-off-by: ATechnoHazard <amolele@gmail.com>

src/core/users/entity.rs

@@ -8,3 +8,14 @@ pub struct User {
     pub password: Option<String>,
     pub activated: Option<bool>,
 }
+
+impl User {
+    pub fn new() -> Self {
+        User {
+            id: "".to_string(),
+            username: None,
+            password: None,
+            activated: None,
+        }
+    }
+}