Update .gitlab-ci.yml

1 job for master in 35 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #52164385
build

00:00:35

 
Name Stage Failure
failed
build Test There has been a runner system failure, please try again
Pulling docker image precise ...
ERROR: Preparation failed: Error: No such image: precise
Will be retried in 3s ...
Using Docker executor with image precise ...
Using docker image sha256:451d5b8d7131514d4f697ff611b5b37a8395f9c32d92bb201aeb6db2bfb47c42 for predefined container...
Pulling docker image precise ...
ERROR: Preparation failed: Error: No such image: precise
Will be retried in 3s ...
ERROR: Job failed (system failure): Error: No such image: precise