Rebase: Write an empty "quiet" file to make C Git happy

C git tries to read this file from the rebase state directory and
complains about it not being there for rebases started by JGit. An empty
'quiet' file represents the (verbose) default.

Change-Id: I1844ccbf8d35442d7a8918b57b67eb9b9efd6352
Signed-off-by: Konrad Kügler <swamblumat-eclipsebugs@yahoo.de>

org.eclipse.jgit/src/org/eclipse/jgit/api/RebaseCommand.java

@@ -145,6 +145,8 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 
 	private static final String INTERACTIVE = "interactive"; //$NON-NLS-1$
 
+	private static final String QUIET = "quiet"; //$NON-NLS-1$
+
 	private static final String MESSAGE = "message"; //$NON-NLS-1$
 
 	private static final String ONTO = "onto"; //$NON-NLS-1$
@@ -928,6 +930,7 @@ public class RebaseCommand extends GitCommand<RebaseResult> {
 		rebaseState.createFile(ONTO, upstreamCommit.name());
 		rebaseState.createFile(ONTO_NAME, upstreamCommitName);
 		rebaseState.createFile(INTERACTIVE, ""); //$NON-NLS-1$
+		rebaseState.createFile(QUIET, ""); //$NON-NLS-1$
 
 		ArrayList<RebaseTodoLine> toDoSteps = new ArrayList<RebaseTodoLine>();
 		toDoSteps.add(new RebaseTodoLine("# Created by EGit: rebasing " + headId.name() //$NON-NLS-1$