Cleanup code

Author: Glavo

buildSrc/src/main/java/org/glavo/hmcl/update/CheckExisting.java

@@ -17,13 +17,8 @@
  */
 package org.glavo.hmcl.update;
 
-import org.gradle.api.DefaultTask;
 import org.gradle.api.logging.Logger;
 import org.gradle.api.logging.Logging;
-import org.gradle.api.provider.Property;
-import org.gradle.api.tasks.Input;
-import org.gradle.api.tasks.TaskAction;
-import org.jetbrains.annotations.NotNull;
 import org.w3c.dom.Document;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;