Damn. this isn't "ensures user enters a adress" it's "ensures user enters anything at all".
It solved exactly 0.
If someone now pastes in the adress with 1 character missing, what happens? You'll say it's valid, and then... you keep the money they send again?

Really, this if(input = any) check doesn't inspire great confidence you actually mix anything at all. But i've said this already.