VSTS build tasks do not work with Sonarqube 7.3

The VSTS Sonarqube build tasks fail with Sonarqube 7.3:

The “Run Code Analysis” task fails with:
WARN: Metric ‘comment_lines_data’ is deprecated. Provided value is ignored.

The “Publish Quality Gate Result” task fails with:
[SQ] API GET ‘/api/ce/task’ failed, status code was: 404
[SQ] Could not fetch task for ID ‘xxxxxxxxxxx’

It seems that an older version of the sonar scanner is used which no longer works with Sonarqube 7.3