fix: set user default group

Signed-off-by: Nicolas FOURNIER <[email protected]>

Author: fehrnah

Diff for: ovh/resource_me_identity_user.go

@@ -39,6 +39,7 @@ func resourceMeIdentityUser() *schema.Resource {
 			"group": {
 				Type:        schema.TypeString,
 				Optional:    true,
+				Default:     "DEFAULT",
 				Description: "User's group",
 			},
 			"login": {