On the fsfs-format7 branch: remove obsolete files.

* subversion/libsvn_fs_fs/index.h,
  subversion/libsvn_fs_fs/index.c: drop

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1507008 13f79535-47bb-0310-9956-ffa450edef68