shells/mksh: R49 -> R50

PR:		191582
Submitted by:	olivierd
Approved by:	miwi (maintainer)


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@366291 35697150-7ecd-e111-bb59-0022644237b5
The port was identical to german/aspell, changed it to the right version.

- Fix comment and desciption
- Bump portepoch (version would have gone backward otherwise)

PR:		180616
Submitted by:	Kalten <kalten@gmx.at>


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@366292 35697150-7ecd-e111-bb59-0022644237b5