make sortorder nullable

Author: dietercoopman

database/migrations/create_inforce_tables.php.stub

@@ -19,7 +19,7 @@ class CreateInforceTables extends Migration
             $table->string('name');
             $table->string('route')->nullable();
             $table->string('permission')->nullable();
-            $table->bigInteger('sort_order');
+            $table->bigInteger('sort_order')->nullable();
             $table->text('icon')->nullable();
             $table->boolean('editable')->default(true);
             $table->timestamps();