add missing closing quote.

Doc/lib/libcodeop.tex

@@ -19,7 +19,7 @@ There are two parts to this job:
 \begin{enumerate}
   \item Being able to tell if a line of input completes a Python 
         statement: in short, telling whether to print
-        `\code{>\code{>}>~} or `\code{...~}' next.
+        `\code{>\code{>}>~}' or `\code{...~}' next.
   \item Remembering which future statements the user has entered, so 
         subsequent input can be compiled with these in effect.
 \end{enumerate}