add more useful error message for hivemq fail

[sgbaird]

https://github.com/sparks-baird/self-driving-lab-demo/issues/245

[coveralls]

Pull Request Test Coverage Report for Build 9797854980

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 47.319%

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Totals
Change from base Build 9797744767:	0.0%
Covered Lines:	304
Relevant Lines:	579

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💛 - Coveralls