I experienced a similar issue (the installer aborted when I answered "No" to the same question) and have found a simple, provisional workaround - see https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/572634/comments/6.
I experienced a similar issue (the installer aborted when I answered "No" to the same question) and have found a simple, provisional workaround - see https:/ /bugs.launchpad .net/ubuntu/ +source/ update- manager/ +bug/572634/ comments/ 6.