Match ec2-bundle-vol on web to code

Issue #248 contained a PR which changes the way bundle_vol_command is
used by default. This change to the defaults was not reflected on the
website, so I encountered the same issue when making changes to the
bundle_vol_command in my config.

website/source/docs/builders/amazon-instance.html.markdown

@@ -238,7 +238,7 @@ sudo -n ec2-bundle-vol \
 	-u {{.AccountId}} \
 	-c {{.CertPath}} \
 	-r {{.Architecture}} \
-	-e {{.PrivatePath}} \
+	-e {{.PrivatePath}}/* \
 	-d {{.Destination}} \
 	-p {{.Prefix}} \
 	--batch