Minor optimization: remove conditional (reduxjs#1131)

* Minor optimization: remove conditional

The conditional in selectDerivedProps is unnecessary. The code behaves
identically now but saves about 10% of performance for that portion of
the function.

See: https://jsperf.com/conditional-vs-not

Code left in place but commented in case someone ever wants to add
something like it back for "clarity".

* Just remove the code

src/components/connectAdvanced.js

@@ -151,10 +151,6 @@ export default function connectAdvanced(
 
         const nextProps = sourceSelector(state, props)
 
-        if (lastDerivedProps === nextProps) {
-          return lastDerivedProps
-        }
-
         lastDerivedProps = nextProps
         return lastDerivedProps
       }