[OE-core] [RFC] remove the subversion_1.6.15.bb

[Rongqing Li]

Hi:

    there are two version subversion in oe-core, Do we have special
need on subversion 1.6.15, if not, I like to remove it

./meta/recipes-devtools/subversion/subversion_1.8.13.bb
./meta/recipes-devtools/subversion/subversion_1.6.15.bb


-Roy
-Roy