fix minor unsafe pointer type assumption issue (#397)
fix minor unsafe pointer type assumption issue (#397)

Motivation:

In a test we did `assumingMemoryBound(to: in6_addr.self)` for something
that was actually bound to `UInt8`. So we should use
`bindMemory(to: in6_addr.self, count: 1)` instead

Modifications:

replace one `assumingMemoryBound` by `bindMemory`

Result:

more memory correctness is good even for tests
apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio