gitlab.sh: Use personal token to tigger pipelines

Since personal tokens are used across the script there is no much gain
in using trigger tokens. The problem with trigger tokens is that they
are per project, and when they expired or are revoked extra work is needed.

Also the current code was buggy since it does not properly handle the
creation of a new trigger token.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>