Added missing \versionchanged tag for the new exclude

parameter.

Doc/lib/libtarfile.tex

@@ -324,6 +324,7 @@ tar archive several times. Each archive member is represented by a
     argument and returns a boolean value. Depending on this value the
     respective file is either excluded (\constant{True}) or added
     (\constant{False}).
+    \versionchanged[Added the \var{exclude} parameter]{2.6}
 \end{methoddesc}
 
 \begin{methoddesc}{addfile}{tarinfo\optional{, fileobj}}