Fix down() for MakeSettingsValueNullable migration. (#4838)

Co-authored-by: Eric Fletcher <[email protected]>

Author: likemusic

migrations/2018_03_16_000000_make_settings_value_nullable.php

@@ -3,6 +3,7 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Schema;
+use Illuminate\Support\Facades\DB;
 
 class MakeSettingsValueNullable extends Migration
 {
@@ -25,6 +26,8 @@ public function up()
      */
     public function down()
     {
+        DB::table('settings')->whereNull('value')->update(['value' => '']);
+
         Schema::table('settings', function (Blueprint $table) {
             $table->text('value')->nullable(false)->change();
         });