Remove deprecated StreamCopyThread#flush

StreamCopyThread: Do not let flush interrupt a write.
flush calls interrupt() to interrupt a pending read and trigger a
flush.  Unfortunately that interrupt() call can also interrupt a
pending write, putting Jsch in a bad state and triggering "Short read
of block" errors.

Change-Id: I11f8a014fd72df06617cc8731d992eb14cc32a67
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/util/io/StreamCopyThread.java

@@ -80,20 +80,6 @@ public class StreamCopyThread extends Thread {
 		writeLock = new Object();
 	}
 
-	/**
-	 * Request the thread to flush the output stream as soon as possible.
-	 * <p>
-	 * This is an asynchronous request to the thread. The actual flush will
-	 * happen at some future point in time, when the thread wakes up to process
-	 * the request.
-	 */
-	@Deprecated
-	public void flush() {
-		synchronized (writeLock) {
-			interrupt();
-		}
-	}
-
 	/**
 	 * Request that the thread terminate, and wait for it.
 	 * <p>