removed deprecated _str function as py2 support has been dropped

update _str references to use builin str instead
update settings.Preferences class for py2 drop

plexapi/settings.py

@@ -101,12 +101,11 @@ class Setting(PlexObject):
     """
     _bool_cast = lambda x: True if x == 'true' or x == '1' else False
     _bool_str = lambda x: str(x).lower()
-    _str = lambda x: str(x).encode('utf-8')
     TYPES = {
         'bool': {'type': bool, 'cast': _bool_cast, 'tostr': _bool_str},
-        'double': {'type': float, 'cast': float, 'tostr': _str},
-        'int': {'type': int, 'cast': int, 'tostr': _str},
-        'text': {'type': str, 'cast': _str, 'tostr': _str},
+        'double': {'type': float, 'cast': float, 'tostr': str},
+        'int': {'type': int, 'cast': int, 'tostr': str},
+        'text': {'type': str, 'cast': str, 'tostr': str},
     }
 
     def _loadData(self, data):
@@ -171,8 +170,5 @@ class Preferences(Setting):
     def _default(self):
         """ Set the default value for this setting."""
         key = '%s/prefs?' % self._initpath
-        if self.type == 'int':
-            url = key + '%s=%s' % (self.id, self.default)
-        else:
-            url = key + '%s=%s' % (self.id, self.default.decode())
+        url = key + '%s=%s' % (self.id, self.default)
         self._server.query(url, method=self._server._session.put)