remove erroneous public domain note

SCCS-file: newstrftime.3
SCCS-SID: 8.3

newstrftime.3

@@ -228,5 +228,3 @@ newtzset(3),
 time(2),
 tzfile(5)
 .\" %W%
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.