x11-wm/compton-yshui: unbreak fetch

Looks like directory name has already changed within the distfile.

> yshui-compton-v7.4_GH0.tar.gz doesn't seem to exist in /portdistfiles/.

> Attempting to fetch https://codeload.github.com/yshui/compton/tar.gz/v7.4?dummy=/yshui-compton-v7.4_GH0.tar.gz

fetch: https://codeload.github.com/yshui/compton/tar.gz/v7.4?dummy=/yshui-compton-v7.4_GH0.tar.gz: size unknown
fetch: https://codeload.github.com/yshui/compton/tar.gz/v7.4?dummy=/yshui-compton-v7.4_GH0.tar.gz: size of remote file is not known
yshui-compton-v7.4_GH0.tar.gz 213 kB 4215 kBps 00s

> Fetched file size mismatch (expected 218899, actual 218898)

> Trying next site

> Attempting to fetch http://distcache.FreeBSD.org/ports-distfiles/yshui-compton-v7.4_GH0.tar.gz

fetch: http://distcache.FreeBSD.org/ports-distfiles/yshui-compton-v7.4_GH0.tar.gz: Not Found

> Couldn't fetch it - please try to retrieve this

> port manually into /portdistfiles/ and try again.

• Error code 1

Reported by: pkg-fallout