Flake8 bugbear fixes (#12072)

* Don't use mutable argument defaults (bugbear B006)

* Use callable(x) instead of hasattr(x, '__call__') (bugbear B004)

* Remove/mark unused loop control variables (bugbear B007)

* Fix stripping protocol from kodi host name (bugbear B005)

* Fix plant daily history add default date (bugbear B008)

tests/test_util/aiohttp.py

@@ -97,7 +97,7 @@ class AiohttpClientMockResponse:
     """Mock Aiohttp client response."""
 
     def __init__(self, method, url, status, response, cookies=None, exc=None,
-                 headers={}):
+                 headers=None):
         """Initialize a fake response."""
         self.method = method
         self._url = url
@@ -107,7 +107,7 @@ class AiohttpClientMockResponse:
         self.response = response
         self.exc = exc
 
-        self._headers = headers
+        self._headers = headers or {}
         self._cookies = {}
 
         if cookies: