branch: use BRANCH_COLOR_LOCAL in ref-filter format

branch: use BRANCH_COLOR_LOCAL in ref-filter format

Since 949af0684 (branch: use ref-filter printing APIs,
2017-01-10), git-branch's output is generated by passing a
custom format to the ref-filter code. This format forgot to
pass BRANCH_COLOR_LOCAL, meaning that local branches
(besides the current one) were never colored at all.

We can add it in the %(if) block where we decide whether the
branch is "current" or merely "local".  Note that this means
the current/local coloring is either/or. You can't set:

  [color "branch"]
  local = blue
  current = bold

and expect the current branch to be "bold blue". This
matches the pre-949af0684 behavior.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>