fix error when birthdate == null

2 jobs for upgrade-sf3 in 44 seconds (queued for 1 minute and 30 seconds)
Status Job ID Name Coverage
  Test
failed #160091
test:php-7.2

00:00:44

 
  Deploy
skipped #160092
deploy-packagist
 
Name Stage Failure
failed
test:php-7.2 Test There is an unknown failure, please try again
Running on runner-a761b9ac-project-2345-concurrent-0 via serveur-2...
Fetching changes...
HEAD is now at e96da0c add email and mobile number to person: last modif and translations
From https://framagit.org/Chill-project/Chill-Person
983ed7a..9bdec63 upgrade-sf3 -> origin/upgrade-sf3
Checking out 9bdec633 as upgrade-sf3...
Skipping Git submodules setup
/bin/bash: line 6: echo: write error: No space left on device
ERROR: Job failed: exit code 1