devel/rlwrap: Update to 0.44

And while here, also:

• Switch to versioned release download
• Reformat Makefile according to portclippy/portfmt
• Fix pkg-plist

Reviewed by: osa (mentor), swills (mentor)
Approved by: osa (mentor)
MFH: 2021Q1
Differential Revision: https://reviews.freebsd.org/D28429