multimedia/droidcam: Update 2.1.4 => 2.1.5
While here, make use of ${DESKTOPDIR} instead.
Changelog:
https://github.com/dev47apps/droidcam-linux-client/releases/tag/v2.1.5
Reviewed by: osa, vvd (mentors)
Approved by: vvd (mentor)
Differential Revision: https://reviews.freebsd.org/D55542