docker-health monitor doesn't work

[jackfrancis]

What this PR does / why we need it: If you define a bash function omitting the function keyword, you need ()

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

If applicable:

• [ ] documentation
• [ ] unit tests
• [ ] tested backward compatibility (ie. deploy with previous version, upgrade with this branch)

Release note:

docker-health monitor doesn't work

[tariq1890]

/lgtm