Actually, this symptom is due to debian/{config,postinst} both being *utterly* broken in behaviour.
In debian/postinst, after the plugin is downloaded and/or installed for the first time, the debconf "httpget" variable is forcibly set to false, which will fail the license agreement query, and hence, the reporter's symptom is exhibited.
debian/config is utterly out of date, still uses md5sums, and attempts to store an invalid/outdated directory into the debconf "local" variable.
Actually, this symptom is due to debian/ {config, postinst} both being *utterly* broken in behaviour.
In debian/postinst, after the plugin is downloaded and/or installed for the first time, the debconf "httpget" variable is forcibly set to false, which will fail the license agreement query, and hence, the reporter's symptom is exhibited.
debian/config is utterly out of date, still uses md5sums, and attempts to store an invalid/outdated directory into the debconf "local" variable.