Fix typo (noticed in Raymond's r54053 commit adding NamedTuple

Doc/lib/libcollections.tex

@@ -16,7 +16,7 @@ Future additions may include balanced trees and ordered dictionaries.
 \subsection{\class{deque} objects \label{deque-objects}}
 
 \begin{funcdesc}{deque}{\optional{iterable}}
-  Returns a new deque objected initialized left-to-right (using
+  Returns a new deque object initialized left-to-right (using
   \method{append()}) with data from \var{iterable}.  If \var{iterable}
   is not specified, the new deque is empty.