[WP] Typo in manual

src/plugins/wp/doc/manual/wp_plugin.tex

@@ -1392,7 +1392,7 @@ The \textsf{WP} options to control session and cache are \verb+-wp-session+ and
   directory \verb+'.frama-c/wp'+ will be used to setup the \textsf{WP} session.
 \item[\tt -wp-cache <mode>] selects the cache mode to use with why3 provers. The default mode is \verb'update'
   if a \textsf{WP} session is set, and \verb+none+ otherwise. The cache entries are stored in the session directory,
-  which is \verb+./frama-c/wp/cache+ by default.
+  which is \verb+./.frama-c/wp/cache+ by default.
 \end{description}
 
 The available cache modes are described below: