Make close brace a paren to match open.

Doc/ref/ref6.tex

@@ -526,7 +526,7 @@ If no expressions are present, \keyword{raise} re-raises the last
 exception that was active in the current scope.  If no exception is
 active in the current scope, a \exception{TypeError} exception is
 raised indicating that this is an error (if running under IDLE, a
-\exception{Queue.Empty} exception is raised instead}.
+\exception{Queue.Empty} exception is raised instead).
 \index{exception}
 \indexii{raising}{exception}