style the scaling not working to fix

back/src/auth/auth.controller.ts

@@ -7,7 +7,7 @@ import {
 	Body,
 	Delete,
 	BadRequestException,
-	UnprocessableEntityException,
+	DuplicateException,
 	HttpCode,
 	Put,
 	InternalServerErrorException,
@@ -77,7 +77,7 @@ export class AuthController {
 		} catch (e) {
 			// check if the error is a duplicate key error
 			if (e.code === 'P2002') {
-				throw new UnprocessableEntityException('Username or email already taken');
+				throw new DuplicateException('Username or email already taken');
 			}
 			console.error(e);
 			throw new BadRequestException();

back/test/robot/auth/auth.robot

@@ -30,7 +30,7 @@ Register Duplicates
     # We can't use the `Register` keyword because it assert for success
     POST    /auth/register    {"username": "user-duplicate", "password": "pass", "email": "mail@kyoo.moe"}
     Output
-    Integer    response status    422
+    Integer    response status    409
     Login    user-duplicate
     [Teardown]    DELETE    /auth/me