[Groff] typo in groff_char.man

[Bruno Haible]

This fixes a typo. UnicodeData.txt has:

03C5;GREEK SMALL LETTER UPSILON;Ll;0;L;;;;;N;;;03A5;;03A5
03C6;GREEK SMALL LETTER PHI;Ll;0;L;;;;;N;;;03A6;;03A6

--- groff-20060204.orig/man/groff_char.man      2006-01-23 22:58:22.000000000 
+0100
+++ groff-20060204/man/groff_char.man   2006-02-13 03:42:17.000000000 +0100
@@ -1275,7 +1275,7 @@
 .
 Starting with Unicode\ 3.0, the reference glyphs have been exchanged and
 described verbally also: In mathematical context, U+03D5 is the stroked
-variant and U+03C5 the curly glyph.
+variant and U+03C6 the curly glyph.
 .
 Unfortunately, most font vendors didn't update their fonts to
 this (incompatible) change in Unicode.