Fix table rule row detection.

src/compare/diff.rs

@@ -1402,6 +1402,7 @@ fn compare_table<'b, 's>(
     // Compare value
     let value = get_property(emacs, ":value")?;
     if value.is_some() {
+        // I don't know what :value is for, but it seems to always be nil. This is here to alert me to value being non-nil so I can investigate.
         this_status = DiffStatus::Bad;
         message = Some(format!("Non-nil value {:?}", value))
     }