Changelog for network-multicast-0.3.2

# 0.3.2 - Restore compatibility with network-2.0 # 0.3.1 - Fix [build errors](https://github.com/commercialhaskell/stackage/issues/4589) # 0.3.0 - Fix compatibility with network-3.0