When first starting the ThinLinc client, the configuration from that release will be written to `~/.thinlinc/tlclient.conf'.
If we decide to change the default configuration values in the next release, the user will have to remove their `tlclient.conf' for these changes to take effect. This makes it problematic for us to roll out new configuration defaults.
One possible approach would be to consider all configuration options that are set to the default value to be unchanged by the user. When a new version is installed, the new defaults replaces the old "unchanged" default values.
When changing this you should also consider what effect it has on configuration migration, as that code can trigger on the existence of variables. Removing them because they have the default value may then cause undesirable side effects.
This also means that ThinLinc administrators does not have the possibility to change UPDATE_URL for their users, such use case could be that they have a customized ThinLinc client.