Change "circularly" to "circulary".

The word "circularly" is not rare, and a mistake for "circular" is
improbable (difference of 2 letters). I suspect that it is an error
coming from commit d978da6e for the
fix of issue #1193, where one previously had

  circularly->circular, circularly,

while this should have been

  circulary->circular, circularly,

as the adjective "circulary" exists (1913 Webster), but is rare and
obsolete (the adjective "circular" is now used instead).