Fix markup typo in a {verbatim} environment (there should not be any!);

caught by Eric Raymond.

Doc/lib/libtime.tex

@@ -235,7 +235,7 @@ in the \rfc{822} Internet email standard.
 
 \begin{verbatim}
 >>> from time import *
->>> strftime("\%a, \%d \%b \%Y \%H:\%M:\%S \%Z", localtime())
+>>> strftime("%a, %d %b %Y %H:%M:%S %Z", localtime())
 'Sat, 27 Jan 2001 05:15:05 EST'
 >>>
 \end{verbatim}