fix bug #75

the databuffer is reused so it might contain junk, therefore only use the
available amount of bytes
(duck)

apps/sam/java/src/net/i2p/sam/SAMv1Handler.java

@@ -758,7 +758,7 @@ public class SAMv1Handler extends SAMHandler implements SAMRawReceiver, SAMDatag
 
         msg.write(("STREAM RECEIVED ID=" + id 
                    +" SIZE=" + len + "\n").getBytes("ISO-8859-1"));
-        msg.write(data);
+        msg.write(data, 0, len);
 
         writeBytes(msg.toByteArray());
     }