Revert "doc/tmac.n: UNIX trademark"

This reverts commit 206f9e43e9.

tmac.n contains a comment asking that modified versions not be
distributed.  So back out the change which updated '.ux' with
the current trademark owner for "UNIX" so that we can continue
distributing with Guidebook.mn.  We'll handle the out of date
trademark issue in another fashion.

doc/tmac.n

@@ -53,13 +53,6 @@
 .\"	occurred when the the "fo" trap position was reset just beneath
 .\"	the current line; the footnote overflow trap would kick in and
 .\"	never be closed.
-.\" **********
-.\" Version 1.6.361	April 15, 2018
-.\"	The version distributed with NetHack 3.6.1 has changed the
-.\"	trademark notice for "UNIX"(tm) [ux macro] to reflect current
-.\"	ownership: The Open Group.  [The pd and vx macros are also long
-.\"	out of date: DEC -> Compaq -> HP -> ? but haven't been changed;
-.\"	need confirmation that Hewlett Packard is the current owner.]
 .\"
 .\"
 .\" **********
@@ -625,8 +618,7 @@
 .	nr ux +1			\" mark footnote as dropped
 \\&\\$2\\s-1UNIX\\s0\\*(rg\\$1
 .	fn				\" put out the footnote
-.\" was "\\&\\*(rgUNIX is a registered trademark of AT&T."
+\\&\\*(rgUNIX is a registered trademark of AT&T.
-\\&\\*(rgUNIX is a registered trademark of The Open Group.
 .	ef				\" short and sweet ...
 .\}
 ..