Sorry Eblyn...you are correct....my reply was slightly inadequate...one needs to delete/move the file. Like Windows you can just change the contents to reflect the new CM name, it is just a plain text file with the CM name (FQDN).
After that you would need to check the installation. On many Linux distributions rexec/rlogin are not installed, so in case the installation server has also changed, then you need to copy the SSH keys from the old IS to new IS and enable SSH in omnirc to perform any install/check/upgrade operations.
I would personally prefer to MOVE the file (to say /tmp) just to avoid confusion and import the host to the new CM.
Cheers,
Nikhil