Fix typo about what method to call when expand_tabs is true.

Doc/lib/libtextwrap.tex

@@ -97,7 +97,7 @@ will be longer than \member{width} characters.
 
 \begin{memberdesc}{expand_tabs}
 (default: \code{True}) If true, then all tab characters in \var{text}
-will be expanded to spaces using the \method{expand_tabs()} method of
+will be expanded to spaces using the \method{expandtabs()} method of
 \var{text}.
 \end{memberdesc}