Update URL

Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>

src/libexpr/eval.cc

@@ -1806,7 +1806,7 @@ void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res)
 Nix attempted to evaluate a function as a top level expression; in
 this case it must have its arguments supplied either by default
 values, or passed explicitly with '--arg' or '--argstr'. See
-https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name],
+https://nixos.org/manual/nix/stable/language/constructs.html#functions.)", symbols[i.name],
                 *fun.lambda.env, *fun.lambda.fun);
             }
         }