Do a truthiness check on references before printing them.

src/renderer/renderer.rs

@@ -99,13 +99,17 @@ impl<'a> DustRenderer<'a> {
             }
             DustTag::DTReference(reference) => {
                 let val = walk_path(breadcrumbs, &reference.path.keys);
-                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val)?;
+                match val {
+                    Err(RenderError::NotFound { .. }) => return Ok("".to_owned()),
+                    Ok(final_val) => {
+                        let loop_elements = final_val.get_loop_elements()?;
                         if loop_elements.is_empty() {
-                    // if let Err(RenderError::NotFound { .. }) = val {
-                    // If reference does not exist in the context, it becomes an empty string
                             return Ok("".to_owned());
                         } else {
-                    return val?.render(&reference.filters);
+                            return final_val.render(&reference.filters);
+                        }
+                    }
+                    Err(render_error) => return Err(render_error),
                 }
             }
             DustTag::DTSection(container) => {