distrodata.bbclass:Fix some recipes upstream version check issue.
Some recipes,like rt-tests,clutter-box2d,iproute2,didn't declare upstream protocal, but in distrodata.bbclass, we use rsync as the default protocal,
this will lead an error when checking upstream version.
Change default protocal from rsync to git in distrodata.bbclass.
Signed-off-by: Mei Lei <lei.mei@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
