[Bugfix] Do not send empty message

cron.py

@@ -38,7 +38,7 @@ def _send(maintainer, message):
     cur.execute(query, (maintainer,))
     discord = cur.fetchone()['discord']
     conn.close()
-    message_json = {"content": message}
+    message_json = {"content": message[:2000]}
     response = requests.post(discord, json=message_json)
     if response.status_code in [200, 204]:
         print("Webhook executed")
@@ -166,7 +166,9 @@ def cron():
                     print(f"item: {item} -> value: {value}")
                     update_missing_value(player['maintainer'], player['player'], item, value)
             time.sleep(2)
-        _send(maintainer['maintainer'], messages)
+        if len(messages) > 0:
+            print(messages)
+            _send(maintainer['maintainer'], messages)
     conn.close()
 
 if __name__ == '__main__':