fix errant verb tense in some messages if pet or mon name ends in 's'

Report stated:
"Poes deliberately slither onto a polymorph trap!" ... it's only one cat, er,
black naga. Why does the parser treat the name as plural? There are lots of
singular words and names that end in -s or -es!

H9249 1780

doc/fixes36.3

@@ -154,6 +154,8 @@ wielded aklys that returned to hero when thrown while inside an engulfer left
 	panic if same weapon killed any engulfer via melee from inside
 uarmh null pointer dereference if a helm of opposite alignment came off due 
 	to being polymorphed
+verb tense was inappropriate in some messages when a mon/pet had a name 
+	ending in 's'
 
 
 Fixes to Post-3.6.2 Problems that Were Exposed Via git Repository