Remove unused imports

These imports are unused since commit
cb349da017

Change-Id: I74ea2a17bf4976d9c74255500e5deeff18208e87
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Clone.java

@@ -47,9 +47,6 @@ import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.text.MessageFormat;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
 
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheCheckout;
@@ -57,7 +54,6 @@ import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.RefComparator;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.TextProgressMonitor;
 import org.eclipse.jgit.revwalk.RevCommit;