change PerlHandler -> PerlResponseHandler in docs

According to
http://perl.apache.org/docs/2.0/user/handlers/http.html#HTTP_Request_Cycle_Phases
"the PerlHandler directive has been renamed to PerlResponseHandler to
better match the corresponding Apache phase name (response)."

lib/Dancer/Deployment.pod

@@ -527,7 +527,7 @@ following:
 
         <Location />
             SetHandler perl-script
-            PerlHandler Plack::Handler::Apache2
+            PerlResponseHandler Plack::Handler::Apache2
             PerlSetVar psgi_app /websites/myapp.example.com/app.pl
         </Location>