PR 41090: jsch-0.1.30 causes SCP task to hang

Contributed by Atsuhiko Yamanaka
jsch 0.1.30 has improved the stream handling internally and it must be flushed
explicitly.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@489755 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -8,6 +8,9 @@ Fixed bugs:
 -----------
 * SPI support in jar was broken.
   Bugzilla report 41201.
+  
+* jsch-0.1.30 causes SCP task to hang
+  Bugzilla report 41090.
 
 Other changes:
 --------------

src/main/org/apache/tools/ant/taskdefs/optional/ssh/ScpToMessage.java

@@ -209,6 +209,7 @@ public class ScpToMessage extends AbstractSshMessage {
         waitForAck(in);
         sendDirectory(directory, in, out);
         out.write("E\n".getBytes());
+        out.flush();
         waitForAck(in);
     }