add metric query changes to fix exception

[viraja1]

Fixes the following issues:-
#3254
#3444

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[Fireant456]

Can we get this pushed, I would really like to not have to build cachet docker myself to fix issues with metrics graphs

[Fireant456]

https://hub.docker.com/repository/docker/fireant456/cachet If anyone needs it temporarily

[jbrooksuk]

Can you fix the conflicts and then I'll merge this :)

[jbrooksuk]

Thank you for your input on Cachet 2.x. We are shifting our attention and resources to Cachet 3.x and will no longer be supporting the 2.x version. If your feedback or issue is relevant to the 3.x series, we encourage you to engage with the new branch.

For more information on the Cachet rebuild and our plans for 3.x, you can read the announcement here.

We appreciate your understanding and look forward to your contributions to the new version.