Harden TestClientWithRequestTimeout
DeadlineExceeded now implements a TimeOut() function,
since https://github.com/golang/go/commit/dc4427f3727804ded270bc6a7a8066ccb3c151d0
Check for this interface, to prevent possibly incorrect failures;
```
00:16:41 --- FAIL: TestClientWithRequestTimeout (0.00s)
00:16:41 client_test.go:259: assertion failed:
00:16:41 --- context.DeadlineExceeded
00:16:41 +++ err
00:16:41 :
00:16:41 -: context.deadlineExceededError{}
00:16:41 +: &net.OpError{Op: "dial", Net: "tcp", Addr: s"127.0.0.1:49294", Err: &poll.TimeoutError{}}
00:16:41
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit c7816c532374ad9461b78b2166922bcd21a3405f)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: 43978cbc7da889e5ea0513ce98aa8f3acaa907ba
Component: engine
Sebastiaan van Stijn
76709cc970