do not preappend app ids with :: so that we can do routing based on the ...

...app id as a host header

We would like to do routing based on the application id as a host header like so:

acl devint-widgetshop-api-aclrule  hdr_beg(host) -m beg -i devint-widgetshop-api

To do this it would be great if the escaped app id was preappended with ::. I thought about adding another field to the struct but I couldn't think of a good reason why it is preappended with :: in the first place.