Question not removed from Questions List macro after label is removed from question

Issue summary:

When a label is removed from a question that has a comment, or an answer, the question still appears on the "Questions List" macro that matches the label that's been removed.

Steps to reproduce:

1. Install Questions for Confluence Plugin.
2. Create a question, and give it at least 2 labels. (Example: Label1, Label2)
3. Now, add a comment, or an "Answer" to the question. (Issue does not occur when there are no comment or "Answer" in the question)
4. In a new page, add the "Questions List" macro, and add one of the label to filter. (Example: Label2)
5. Now go and remove the label, "Label2" from the question.
   1. Note: We need to edit the question and remove the label, and not remove the label directly by clicking on the Pencil icon.
   2. Issue does not occur if we remove the label using the Pencil icon, without Editing the question.
6. You will see that the question still shows up in the "Questions List" macro.

Expected behavior

1. Question gets removed from the "Questions List" macro when the matching label is removed.

Current behavior

1. Question does not get removed from the "Questions List" macro when the matching label is removed.

Workaround

1. Use the Pencil icon to remove the label in the fist place, without editing the question.
2. If the question is edited and removed, add back the label and remove it again using the Pencil icon.
3. Clear the plugin cache and re-index Confluence from scratch.