Fix #208 breaking changes to 'slices.SortFunc'

[KEINOS]

Fix of the below error on module update (#208)

$ go test ./...
# github.com/multiformats/go-multiaddr
./multiaddr.go:223:25: type func(a Multiaddr, b Multiaddr) bool of func(a, b Multiaddr) bool {…} does not match inferred type func(a Multiaddr, b Multiaddr) int for func(a E, b E) int
FAIL    github.com/multiformats/go-multiaddr [build failed]
FAIL    github.com/multiformats/go-multiaddr/net [build failed]
FAIL

[KEINOS]

dup of #207

closing.

[KEINOS]

fixed in #210