Sets the ldap_default_group field to nullable and default null

Signed-off-by: snipe <snipe@snipe.net>

database/migrations/2022_12_20_171851_fix_nullable_migration_for_settings.php

@@ -0,0 +1,30 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class FixNullableMigrationForSettings extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('settings', function (Blueprint $table) {
+            $table->string('ldap_default_group')->nullable()->default(null)->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        // nothing to do here - this is a hotfix
+    }
+}