The registry entries in HKEY_LOCAL_MACHINE\SOFTWARE\Altiris\Communications\Servers are created automatically when agent or some solution plugin tries connecting to a server, this can ne SMP server or Pckager Server or Task Server or any other server. These are the server profiles record the agent uses to ping servers and do speed checks later.
You can stop the agent, remove the registry entries but they will start appearing as soon as agent makes connection to a server.
In this case seems SK is right, HTTPS address is received as part of some package codebases. SMP server sends all the possible codebases to the agents regardless of certificate presense on the agent. The only pre-confition for this is binding to SSL port in IIS on SMP server, that's why SMCC solution above helps.
This behavior is new in 7.5 compare to 7.1. Unfortunatelly there is no way for now to turn it off.