Needed to build with newer go toolchains (up to 1.19). Many of the
libp2p subpackages have been merged as sub-directories of the main
libp2p package so update the imports to use the newer versions.
Fixes https://github.com/certusone/wormhole/issues/305
The logic to do this seemingly simple task is hilariously complex
due to the version string being attacker-controlled.
Change-Id: Ia1758418a67c082595affe0b7f2bb801e9434733