fix unhandled errors in app_test.go

[Kamandlou]

No description provided.

[efectn]

I don't think we need to handle errors for Send(). It always returns nil. https://github.com/gofiber/fiber/blob/master/ctx.go#L1437

[Kamandlou]

I don't think we need to handle errors for Send(). It always returns nil. https://github.com/gofiber/fiber/blob/master/ctx.go#L1437

Yes, it is not needed now, but there may be changes in this method that are needed in the future