S1 OSV download fails with >20 concurrent operations

[johntruckenbrodt]

Occasionally the EOF OSV files downloaded from https://scihub.copernicus.eu/gnss via pyroSAR.S1.OSV contain an error message when the dedicated user account gnssguest is used in >20 parallel operations:

<?xml version='1.0' encoding='UTF-8'?>
<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
    <code/>
    <message xml:lang="en">An exception occured while creating a stream: Maximum number of 20 
        concurrent flows achieved by the user "gnssguest"
    </message>
</error>

downloaded file: S1B_OPER_AUX_POEORB_OPOD_20210301T141122_V20190314T225942_20190316T005942.EOF

Optimally pyroSAR would read the file content and retry the download if this error message occurs.