eaMuCommaLambda documentation fix

The description for eaMuCommaLambda described a selection between both offspring and population, mistakenly. Fixed to only offspring (and double checked that the implementation indeed selects from only the offspring)

deap/algorithms.py

@@ -376,7 +376,7 @@ def eaMuCommaLambda(population, toolbox, mu, lambda_, cxpb, mutpb, ngen,
     the evolutionary loop begins by producing *lambda_* offspring from the
     population, the offspring are generated by the :func:`varOr` function. The
     offspring are then evaluated and the next generation population is
-    selected from both the offspring **and** the population. Finally, when
+    selected from **only** the offspring. Finally, when
     *ngen* generations are done, the algorithm returns a tuple with the final
     population and a :class:`~deap.tools.Logbook` of the evolution.