MFH: r454594

sysutils/battray: Update to 2.3

The last update was a no-op. Pointy hat to myself.

Switch to GitHub and mitigate the need of a manual commit-adjustment
for an update.

PR: 223624
Reported by: mat, bsd@mkfs.nl
Reviewed by: bsd@mkfs.nl

Approved by: ports-secteam (swills)