git: e188971328b0..b37eb25116f9 - vendor/zlib - vendor branch updated

[Xin LI]

The branch vendor/zlib has been updated by delphij:

URL: https://cgit.FreeBSD.org/src/log/?id=e188971328b0..b37eb25116f9

b37eb25116f9 Vendor import of zlib 1.3.