fix the copyright string years

#                            | (__| |_| |  _ <| |___ 

#                             \___|\___/|_| \_\_____|

#

# Copyright (C) 2002, Daniel Stenberg, <daniel@haxx.se>, et al.

# Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.

#

# In order to be useful for every potential user, curl and libcurl are

# dual-licensed under the MPL and the MIT/X-derivate licenses.