Following up on r1603485, make the 'db/current' parsing within the
svn_fs_fs__read_current() routine stricter.

* subversion/libsvn_fs_fs/util.c
  (svn_fs_fs__read_current): Expect a newline after the revision number
    for new FS formats and after the next-copy-id for old formats.  A well-
    formed 'db/current' file always includes a trailing newline.  Raise an
    error when it is absent.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1603605 13f79535-47bb-0310-9956-ffa450edef68