Please do not .gz manpages

Submitted by Michał Górny

Assigned to Sean Davis @bluesabre

Link to original bug (#16378)

Description

Many of the modern systems use a better compressor than .gz and/or filesystem-level compression. Furthermore, most of modern distros have their own hooks for compressing manpages. Therefore, please remove the Makefile rule which forces .gz compression and install the manpage uncompressed.