Revert "Fixed issue with stdin flush for libssh clients"

This reverts commit c2554cf.

Author: pkittenis

ci/integration_tests/ssh/test_single_client.py

@@ -332,11 +332,3 @@ def _disc():
         client._disconnect_eagain = _disc
         client._connect_init_session_retry(0)
         client.disconnect()
-
-    def test_stdin(self):
-        host_out = self.client.run_command('read line; echo $line')
-        host_out.stdin.write('a line\n')
-        host_out.stdin.flush()
-        self.client.wait_finished(host_out)
-        stdout = list(host_out.stdout)
-        self.assertListEqual(stdout, ['a line'])

pssh/clients/base/single.py

@@ -68,8 +68,6 @@ def write(self, data):
 
     def flush(self):
         """Flush pending data written to stdin."""
-        if not hasattr(self._channel, "flush"):
-            return
         return self._client._eagain(self._channel.flush)