[SaaS] Update link to purge-by-hostname in troubleshooting.mdx (#25399)

Hello team, 

The context here is to purge cache by hostnames.

https://developers.cloudflare.com/cache/how-to/purge-cache/purge-by-hostname/

Thanks!

Author: nenizera

src/content/docs/cloudflare-for-platforms/cloudflare-for-saas/reference/troubleshooting.mdx

@@ -21,7 +21,7 @@ If you require a higher rate limit, contact your Customer Success Manager.
 
 ## Purge cache
 
-To remove specific files from Cloudflare’s cache, [purge the cache](/cache/how-to/purge-cache/purge-by-single-file/) while specifying one or more hosts.
+To remove specific files from Cloudflare’s cache, [purge the cache](/cache/how-to/purge-cache/purge-by-hostname/) while specifying one or more hostnames.
 
 ***
 
@@ -124,4 +124,4 @@ Since no host is 64 characters or fewer, Cloudflare Branding is required. Please
 
 To solve this, you can set `cloudflare_branding` to `true` when [creating your custom hostnames](/cloudflare-for-platforms/cloudflare-for-saas/domain-support/create-custom-hostnames/#hostnames-over-64-characters) via API.
 
-Cloudflare branding means that `sni.cloudflaressl.com` will be added as the certificate Common Name (CN) and the long hostname will be included as a part of the Subject Alternative Name (SAN).
+Cloudflare branding means that `sni.cloudflaressl.com` will be added as the certificate Common Name (CN) and the long hostname will be included as a part of the Subject Alternative Name (SAN).