man page has wrong default for MinUptimeHidServDirectoryV2

In #14149 (moved) (Tor 0.2.6.3-alpha) we changed the default for MinUptimeHidServDirectoryV2 to 96 hours, to reflect that the directory authorities had already changed it manually. We changed the spec too. But we forgot to change the man page.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information