Length of query results should be larger than 0 for there to be entries

Length of query results should be larger than 0 for there to be entries, not 1.

See:

• https://git.gfz-potsdam.de/dynamicexposure/globaldynamicexposure/gde-core/-/blob/master/gdecore/database_queries.py#L586
• https://git.gfz-potsdam.de/dynamicexposure/globaldynamicexposure/gde-core/-/blob/master/gdecore/database_queries.py#L710

Replace:

len(exec_result) > 1

with:

len(exec_result) > 0