SFTP: support old versions of paramiko

Conflicts:
	product/ERP5Type/ConnectionPlugin/SFTPConnection.py

product/ERP5Type/ConnectionPlugin/SFTPConnection.py

@@ -111,7 +111,15 @@ class SFTPConnection:
     filepath = os.path.join(path, filename)
     serialized_data = Binary(str(data))
     try:
-      self.conn.putfo(StringIO(str(serialized_data)), filepath, confirm=confirm)
+      if hasattr(self.conn, 'putfo'):
+        # paramiko >= v1.10.0
+        self.conn.putfo(StringIO(str(serialized_data)), filepath, confirm=confirm)
+      else:
+        # older paramiko version
+        with tempfile.NamedTemporaryFile() as tmpfile:
+          tmpfile.write(str(serialized_data))
+          tmpfile.flush()
+          self.conn.put(tmpfile.name, filepath)
     except error, msg:
       raise SFTPError(str(msg) + ' while writing file %s on %s' % (filepath, path, self.url))