fix checkstyle

Author: bernardodemarco

api/src/main/java/org/apache/cloudstack/api/command/admin/user/RegisterUserKeysCmd.java

@@ -17,7 +17,6 @@
 package org.apache.cloudstack.api.command.admin.user;
 
 import com.cloud.event.EventTypes;
-import com.cloud.exception.InvalidParameterValueException;
 import com.cloud.user.Account;
 import com.cloud.user.User;
 import org.apache.cloudstack.acl.Rule;