fixup! Define __getattribute__() instead of __getattr__() on slotted classes with cached properties

Author: dlax

docs/how-does-it-work.md

@@ -111,7 +111,7 @@ Therefore, *attrs* converts `cached_property`-decorated methods when constructin
 Getting this working is achieved by:
 
 * Adding names to `__slots__` for the wrapped methods.
-* Adding a `__getattr__` method to set values on the wrapped methods.
+* Adding a `__getattribute__` method to set values on the wrapped methods.
 
 For most users, this should mean that it works transparently.