[10.x] fix mysql

Author: rez1dent3

tests/migrations/2018_11_08_214421_create_items_table.php

@@ -14,7 +14,7 @@ public function up(): void
             $table->string('name');
             $table->integer('price');
             $table->json('prices')
-                ->default('[]');
+                ->nullable();
             $table->unsignedSmallInteger('quantity');
             $table->timestamps();
         });