added importer for Gewerkschaftshaus erfurt

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.cal.db/src/main/java/de/srsoftware/cal/db/MariaDB.java

@@ -12,7 +12,6 @@ import static de.srsoftware.tools.jdbc.Query.*;
 import static java.lang.System.Logger.Level.*;
 
 import de.srsoftware.cal.BaseAppointment;
-import de.srsoftware.cal.Util;
 import de.srsoftware.cal.api.Appointment;
 import de.srsoftware.cal.api.Attachment;
 import de.srsoftware.cal.api.Link;