dev-python/gnuplot-py: Revbump post dep change

Signed-off-by: Michał Górny <mgorny@gentoo.org>

diff --git a/dev-python/gnuplot-py/gnuplot-py-1.8-r1.ebuild b/dev-python/gnuplot-py/gnuplot-py-1.8-r2.ebuild
similarity index 100%
rename from dev-python/gnuplot-py/gnuplot-py-1.8-r1.ebuild
rename to dev-python/gnuplot-py/gnuplot-py-1.8-r2.ebuild