Bump nad_receiver version (#34400)

nad_receiver received a few fixes in 0.0.12, which enables the integration
for me. I assume it may depend on the receiver model, but my receiver only reports
mute state and volume when it's on, while the library used to assume to always
get a reply. With 0.0.11 the nad integration simply excepts on startup,
after bumping the version up it works.

Fixes this:
2020-04-18 22:59:38 ERROR (MainThread) [homeassistant.components.media_player] nad: Error on device update!
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 324, in _async_add_entity
    await entity.async_device_update(warning=False)
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 476, in async_device_update
    await self.hass.async_add_executor_job(self.update)
  File "/usr/local/lib/python3.7/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/nad/media_player.py", line 195, in update
    if self._nad_receiver.main_mute("?") == "Off":
  File "/usr/local/lib/python3.7/site-packages/nad_receiver/__init__.py", line 71, in main_mute
    return self.exec_command('main', 'mute', operator, value)
  File "/usr/local/lib/python3.7/site-packages/nad_receiver/__init__.py", line 62, in exec_command
    return msg.decode().strip().split('=')[1]
IndexError: list index out of range

homeassistant/components/nad/manifest.json

@@ -2,6 +2,6 @@
   "domain": "nad",
   "name": "NAD",
   "documentation": "https://www.home-assistant.io/integrations/nad",
-  "requirements": ["nad_receiver==0.0.11"],
+  "requirements": ["nad_receiver==0.0.12"],
   "codeowners": []
 }

requirements_all.txt

@@ -905,7 +905,7 @@ mycroftapi==2.0
 n26==0.2.7
 
 # homeassistant.components.nad
-nad_receiver==0.0.11
+nad_receiver==0.0.12
 
 # homeassistant.components.keenetic_ndms2
 ndms2_client==0.0.11