whoopsie reuses CRASH_DB_IDENTIFIER on next run

On Vivid, Ubuntu 15.04, I observed the following behavior.

bdmurray@blacklightning:~/Downloads$ sudo stop whoopsie
[sudo] password for bdmurray:
whoopsie stop/waiting
bdmurray@blacklightning:~/Downloads$ sudo CRASH_DB_URL=https://daisy.staging.ubuntu.com CRASH_DB_IDENTIFIER=deadbeefbd89cc5da1f045978a550ad4b38782c1390ccd8c265c5ddc803be1d8bc0d0d5657350ce06c611975d77dac5a28db5e78921476be5430e0b6c1a44dfd APPORT_REPORT_DIR=/var/crash/ whoopsie -f
[11:07:17] Using lock path: /var/crash/whoopsie_lock
[11:07:18] The default IPv4 route is: /org/freedesktop/NetworkManager/ActiveConnection/39
[11:07:18] Not a paid data plan: /org/freedesktop/NetworkManager/ActiveConnection/39
[11:07:18] Found usable connection: /org/freedesktop/NetworkManager/ActiveConnection/39
[11:07:18] online
bdmurray@blacklightning:~/Downloads$ sudo cat /var/lib/whoopsie/whoopsie-id
deadbeefbd89cc5da1f045978a550ad4b38782c1390ccd8c265c5ddc803be1d8bc0d0d5657350ce06c611975d77dac5a28db5e78921476be5430e0b6c1a44dfd
bdmurray@blacklightning:~/Downloads$ sudo start whoopsie
whoopsie start/running, process 9083
bdmurray@blacklightning:~/Downloads$ sudo cat /var/lib/whoopsie/whoopsie-id
deadbeefbd89cc5da1f045978a550ad4b38782c1390ccd8c265c5ddc803be1d8bc0d0d5657350ce06c611975d77dac5a28db5e78921476be5430e0b6c1a44dfd

Notice, how the same CRASH_DB_IDENTIFIER was used by whoopsie when starting up, rather than calculating the system identifier. This may lead to crashes being reported under the wrong system-identifier if people switch from setting the environmental variable to just running whoopsie.