fix conditions when conditions contain index key
fix conditions when conditions contain index key

Take a look at this comment
https://github.com/baopham/laravel-dynamodb/issues/35#issuecomment-262713695
zoul0813/laravel-dynamodb,zoul0813/laravel-dynamodb,zoul0813/laravel-dynamodb,baopham/laravel-dynamodb,baopham/laravel-dynamodb,baopham/laravel-dynamodb