$\infty-\infty$ is indetermonate expression, one has to find this limit carefully, here is one way:
Let $n=1/t$, then $$L=\lim_{t\rightarrow 0} \left(1/t-\frac{1}{et}(1+t)^{1/t}\right),$$
Using the Mclaurin Expansion: $(1+t)^{1/t}=e-et/2+11et^2/24+...$, we get $$L=1/t-\frac{1}{et}(e-et/2+11et^2/24)= \lim_{t\rightarrow 0}( 1/2-11t/24+...)=1/2.$$