fix(mssql): when updating an object by id, omit the id itself

It is a useless update and id is an identity column in MSSQL,
which is not updatable and throws an error if you try.

This affects the following seven objects (Models):
- Category
- CustomFilter
- Group
- Project
- Subtask
- TaskExternalLink
- User

app/Model/CategoryModel.php

@@ -170,7 +170,9 @@ class CategoryModel extends Base
      */
     public function update(array $values)
     {
-        return $this->db->table(self::TABLE)->eq('id', $values['id'])->save($values);
+        $updates = $values;
+        unset($updates['id']);
+        return $this->db->table(self::TABLE)->eq('id', $values['id'])->save($updates);
     }
 
     /**