No data sources shown right after start

[AliceBalfanz]

When launching cate webui on localhost, initially I do not receive any datasets:

I need to first select ESA CCI Open Data Portal Legacy data store and after going back to ESA CCI Open Data Portal data store I get a list of dataset collections.

I would expect the display of the dataset collections right away for the data store which is selected by default.

[AliceBalfanz]

This issue does not exist with the newest changes on master.

[forman]

Seems to be gone. Reopen if issue comes back.

[AliceBalfanz]

This problem now only seems to exist for File Data Sources:
To reproduce:

1. Select File Data Source, add a local file source in case you have none
2. close window
3. reopen: the user preference of last viewed sources being File Data Source is restored, however without the corresponding sources.
   
4. to get the list,you first need to select ESA CCI Open Data Portal and then back to File Data Source

[TonioF]

Solved by #99

[forman]

The issue is back for any selected data source.

[forman]

Cannot reproduce in current version. Reopen if needed!

[forman]

It's back again. Need to find easy way to reproduce.

[TonioF]

Some observations on this:

• It does not seem to appear when you run the Python backend on your local machine
• It does not appear when data is loaded for the first store in the selection list (which is the cci odp store at the time of writing)
• When the local store ("File Data Sources") is selected, the user will not be informed that no data was loaded, but instead be given the wrong information that there is no local data
• It seems that data sources are eventually loaded - but it is always the data sources of the first data store, regardless of which one is selected