🐛 fixes crash in Dashbot plugin caused by non-JSON responses

[palle-k]

Proposed Changes

We noticed a frequent error coming from the catch block of the DashbotAnalyticsPlugin.
This was apparently caused by 502 Bad Gateway errors returned by Dashbot, which have a HTML formatted body.

This PR introduces safeguards that prevent the catch block from crashing when a non-JSON response is returned by Dashbot.

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

[jankoenig]

Thank you!