US2020 Census Data has odd default value

[sturmkev]

In the config field "US Census APIkey" the node uses a plain string as a default value. This doesn't work, if the user doesn't change this. Either we make this string like a gray colored recommendation, which is actually not treated as a string upon execution OR we leave it empty, since the node works that way already.

Additionally, we would need to adapt the resulting error message, which is not giving a proper hint on what might be wrong (see screenshot below).