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##### SUMMARY
If you don't have an ssh client installed in container image or on your system, ansible just throws following error -  `The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'` error. 

```
TASK [Gathering Facts] *********************************************************
[WARNING]: Unhandled error in Python interpreter discovery for host <hostname1>: [Errno 2] No such file or directory: b'ssh': b'ssh'

[WARNING]: Unhandled error in Python interpreter discovery for host <hostname2>: [Errno 2] No such file or directory: b'ssh': b'ssh'

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname1>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname2>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.6
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
Run playbook on the system where ssh client is not installed & playbook is expecting to use ssh keys for remote hosts.


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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
If possible adding an error message indicating `ssh client is not installed on the system`

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Error message mentioned in the summary 
The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
```

Thank you!!
for opt in (u'ssh_common_args', u'{0}_extra_args'.format(binary)):
            attr = getattr(self._play_context, opt, None)
            if attr is not None:
                b_args = [to_bytes(a, errors='surrogate_or_strict') for a in self._split_ssh_args(attr)]
                self._add_args(b_command, b_args, u"PlayContext set %s" % opt)
        
        
        controlpersist, controlpath = self._persistence_controls(b_command)
        if controlpersist:
            self._persistent = True
            if not controlpath:
                cpdir = unfrackpath(self.control_path_dir)
                b_cpdir = to_bytes(cpdir, errors='surrogate_or_strict')
                
                makedirs_safe(b_cpdir, 0o700)
                if not os.access(b_cpdir, os.W_OK):
                    raise AnsibleError("Cannot write to ControlPath %s" % to_native(cpdir))
                if not self.control_path:
                    self.control_path = self._create_control_path(
                        self.host,
                        self.port,
                        self.user
                    )
                b_args = (b"-o", b"ControlPath=" + to_bytes(self.control_path % dict(directory=cpdir), errors='surrogate_or_strict'))
                self._add_args(b_command, b_args, u"found only ControlPersist; added ControlPath")
        
        if other_args:
            b_command += [to_bytes(a) for a in other_args]
        return b_command
    def _send_initial_data(self, fh, in_data, ssh_process):