man page: remove out-of-date COPYRIGHT section

The information previously listed here didn't match what is present in
the source code or the COPYING file, and the X(7) man page doesn't list
any license information as this had claimed.
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

man/xfontsel.man

@@ -215,10 +215,6 @@ parsed.  An error message indicating a missing menu is printed
 to stderr but otherwise nothing bad (or good) happens.
 .PP
 The average-width menu is too large to be useful.
-.SH COPYRIGHT
-Copyright 1989, 1991,  X Consortium
-.PP
-See \fIX(__miscmansuffix__)\fP for a full statement of rights and permissions.
 .SH AUTHOR
 .PP
 Ralph R. Swick, Digital Equipment Corporation/MIT Project Athena