cron broken after PHP update

After a PHP update (5.6.18), cron.php stopped updating tweets.

The console output is:

archivemytweets@Hydrogen:~$ php /home/archivemytweets/archive-my-tweets/cron.php
Importing from Twitter Archive JS Files...
No Twitter Archive JS files found.
HTTP/1.1 200 OK
cache-control: no-cache, no-store, must-revalidate, pre-check=0, post-check=0
content-disposition: attachment; filename=json.json
content-length: 826301
content-type: application/json;charset=utf-8
date: Tue, 01 Mar 2016 20:51:22 GMT
expires: Tue, 31 Mar 1981 05:00:00 GMT
last-modified: Tue, 01 Mar 2016 20:51:22 GMT
pragma: no-cache
server: tsa_b
set-cookie: lang=fr; Path=/
set-cookie: guest_id=<redacted>; Domain=.twitter.com; Path=/; Expires=Thu, 01-Mar-2018 20:51:22 UTC
status: 200 OK
strict-transport-security: max-age=631138519
x-access-level: read
x-connection-hash: <redacted>
x-content-type-options: nosniff
x-frame-options: SAMEORIGIN
x-rate-limit-limit: 180
x-rate-limit-remaining: 173
x-rate-limit-reset: 1456866176
x-response-time: 366
x-transaction: <redacted>
x-twitter-response-tags: BouncerCompliant
x-xss-protection: 1; mode=block
cache-control: no-cache, no-store, must-revalidate, pre-check=0, post-check=0
content-disposition: attachment; filename=json.json
content-length: 826301
content-type: application/json;charset=utf-8
date: Tue, 01 Mar 2016 20:51:22 GMT
expires: Tue, 31 Mar 1981 05:00:00 GMT
last-modified: Tue, 01 Mar 2016 20:51:22 GMT
pragma: no-cache
server: tsa_b
set-cookie: lang=fr; Path=/
set-cookie: guest_id=<redacted>; Domain=.twitter.com; Path=/; Expires=Thu, 01-Mar-2018 20:51:22 UTC
status: 200 OK
strict-transport-security: max-age=631138519
x-access-level: read
x-connection-hash: <redacted>
x-content-type-options: nosniff
x-frame-options: SAMEORIGIN
x-rate-limit-limit: 180
x-rate-limit-remaining: 173
x-rate-limit-reset: 1456866176
x-response-time: 366
x-transaction: <redacted>
x-twitter-response-tags: BouncerCompliant
x-xss-protection: 1; mode=block