Clear score for lack of valid comments

If ChatGPT provides no valid review comments that align with the
directives, the Change Set score is reset to 0.

Jira-Id: IT-103
Change-Id: I2a4097bc4a3384763ddc401e2e13962cedd03436
Signed-off-by: Patrizio <patrizio.gelosi@amarulasolutions.com>
diff --git a/src/main/java/com/googlesource/gerrit/plugins/chatgpt/PatchSetReviewer.java b/src/main/java/com/googlesource/gerrit/plugins/chatgpt/PatchSetReviewer.java
index 4c3b2a5..f9471c0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/chatgpt/PatchSetReviewer.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/chatgpt/PatchSetReviewer.java
@@ -123,7 +123,12 @@
     }
 
     private Integer getReviewScore() {
-        return config.isVotingEnabled() && !reviewScores.isEmpty() ? Collections.min(reviewScores) : null;
+        if (config.isVotingEnabled()) {
+            return reviewScores.isEmpty() ? 0 : Collections.min(reviewScores);
+        }
+        else {
+            return null;
+        }
     }
 
 }