newvers: remove references to svnliteversion

svnliteversion was provided by the base system copy of subversion,
which was disabled in a2bc17474b96 ("Disable building svnlite(1) by
default.")

Reviewed by: zlei
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D42034

(cherry picked from commit 826d1446791816fcaa9be59aedc7295ffbc8d5bb)