SF bug #1567976 : fix typo(backport from r52048)

Since this paragraph is about exception's message attribute(2.5 feature),
I will not backport to 2.4 branch.

Doc/tut/tut.tex

@@ -3539,7 +3539,7 @@ be accessed or printed directly without having to reference \code{.args}.
 
 But use of \code{.args} is discouraged.  Instead, the preferred use is to pass
 a single argument to an exception (which can be a tuple if multiple arguments
-are needed) and have it bound to the \code{message} attribute.  One my also
+are needed) and have it bound to the \code{message} attribute.  One may also
 instantiate an exception first before raising it and add any attributes to it
 as desired.