Fix SQL command quotes

src/docs/self-hosted/troubleshooting.mdx

@@ -128,8 +128,8 @@ docker compose run --rm -T postgres bash -c "apt update && apt install -y --no-i
 ```
 
 If the script above still does not clear up enough disk space, you can try the following in Postgres. This will lead to data loss in event details. _SENTRY_RETENTION_DAYS_ will need to be filled in manually.
-```shell
-DELETE FROM public.nodestore_node WHERE “timestamp” < NOW() - INTERVAL ‘[SENTRY_RETENTION_DAYS]’;
+```sql
+DELETE FROM public.nodestore_node WHERE "timestamp" < NOW() - INTERVAL '[SENTRY_RETENTION_DAYS]';
 VACUUM FULL public.nodestore_node;
 ```
 
@@ -140,7 +140,7 @@ VACUUM FULL actively compacts tables by writing a complete new version of the ta
 There may be some circumstances which you may want to increase or decrease healthcheck interval, timeout or retries for your custom needs. This can be achieved by editing `HEALTHCHECK_INTERVAL`, `HEALTHCHECK_TIMEOUT`, `HEALTHCHECK_RETRIES` variables' values in `.env`.
 
 Occasionally, you might see an error like this
-```shell
+```
 container for service "${servicename}" is unhealthy
 ```