sqlExport: Use FROM DUAL in insertDistinct to fix older mariadb

sqlExport.py

@@ -32,7 +32,7 @@ def insertDistinctFromTableMap(table, data, tableMap):
     # TODO: this could probably be done better as a single statement?
     c.executemany(
        f"""INSERT INTO {table} ({','.join(f'`{k}`' for k in tableMap.keys())})
-        SELECT {','.join(len(tableMap) * ['%s'])}
+        SELECT {','.join(len(tableMap) * ['%s'])} FROM DUAL
         WHERE NOT EXISTS (
             SELECT 1 from {table}
             WHERE {' AND '.join(f'`{k}`<=>%s' for k in tableMap.keys())}