request.is() not work with multipary/form-data boundary include slash
this is not working
```
multipart/form-data; boundary=b/QeEbFgqK9PCZo4T/eXv7f.T74SHd5MxCZ846AsTz-yNV0xrRR_Zks4fkNMCzJck9ZE8o
```

this ok

```
multipart/form-data; boundary=hQ9mmyU9285lg8QhbF7zuDmeuvc8flGel8sSgjHTBinO72dLucgB7oUOC3l6070sPpd1Es
```