xbps-src: remove WIP repo delta support.

- it never worked correctly
- it's WIP and looks like it will be stalled forever
- won't be necessary anymore with xbps-0.42

common/xbps-src/shutils/chroot.sh

@@ -187,7 +187,6 @@ chroot_handler() {
     else
         [ -n "$XBPS_CROSS_BUILD" ] && arg="$arg -a $XBPS_CROSS_BUILD"
         [ -n "$XBPS_KEEP_ALL" ] && arg="$arg -C"
-        [ -n "$XBPS_REPO_DELTAS" ] && arg="$arg -D"
         [ -n "$NOCOLORS" ] && arg="$arg -L"
         [ -n "$XBPS_BUILD_FORCEMODE" ] && arg="$arg -f"
         [ -n "$XBPS_MAKEJOBS" ] && arg="$arg -j$XBPS_MAKEJOBS"