契約作成時のカスタムい識別子バリデーション修正

必須から任意へ

app/Http/Controllers/Web/Contract/CreateParam.php

@@ -17,7 +17,7 @@ class CreateParam extends BaseParam
         return
             [
                 Contract::COL_NAME_NAME => $this->str(),
-                Contract::COL_NAME_CUSTOM => $this->str(),
+                Contract::COL_NAME_CUSTOM => $this->str(true),
             ];
     }
 }