fix trailing whitespace

core/src/lib.rs

@@ -749,7 +749,7 @@ impl syn::parse::Parse for OverridePath {
             Ok(expr) => Ok(OverridePath::Expr(expr)),
             Err(mut err) => {
                 err.combine(Error::new(
-                    input.span(), 
+                    input.span(),
                     "Expected either a `Path` or an `Expr` that evaluates to something compatible with `Into<String>`."
                 ));
                 Err(err)