Error when providers in in summaries

[m-mohr]

Example: https://openeo-dev.eodc.eu/openeo/1.1.0/collections/sentinel-2-l1c

Results in:

formatters.js:911 Field 'providers' with value '[object Object],[object Object]' resulted in an error TypeError: list.map is not a function
    at Object.toList (formatters.js:69:1)
    at Object.formatProviders [as formatter] (formatters.js:445:1)
    at format (formatters.js:949:1)
    at formatters.js:881:1