Update src/rules.jl

Co-authored-by: David Widmann <[email protected]>

Author: mcabbott

src/rules.jl

@@ -255,5 +255,4 @@ end
     :(z = LogExpFunctions.logsubexp($x, $y); $x > $y ? exp($x - z) : -exp($x - z)),
     :(z = LogExpFunctions.logsubexp($x, $y); $x > $y ? -exp($y - z) : exp($y - z))
 
-# only defined in LogExpFunctions >= 0.3.2
 @define_diffrule LogExpFunctions.xlog1py(x, y) = :(log1p($y)), :($x / (1 + $y))