removing unused import

CityDoctorParent/CityDoctorValidation/src/main/java/de/hft/stuttgart/citydoctor2/check/Checker.java

@@ -49,7 +49,6 @@ import org.w3c.dom.Document;
 
 import de.hft.stuttgart.citydoctor2.check.error.SchematronError;
 import de.hft.stuttgart.citydoctor2.checkresult.utility.CheckReportWriteException;
-import de.hft.stuttgart.citydoctor2.checks.CheckPrototype;
 import de.hft.stuttgart.citydoctor2.checks.Checks;
 import de.hft.stuttgart.citydoctor2.checks.SvrlContentHandler;
 import de.hft.stuttgart.citydoctor2.checks.util.FeatureCheckedListener;