Apply suggestion from @RoRoJ

Co-authored-by: Rowena Jones <[email protected]>

Author: SamyOubouaziz

pages/serverless-containers/troubleshooting/cannot-access-container.mdx

@@ -19,7 +19,7 @@ I am experiencing issues while accessing my Serverless Containers.
 
 ## Possible causes
 
-- The container returns A DNS error or issue
+- The container returns a DNS error or issue
 - The container response time is abnormally long
 - The container returns a `HTTP 5xx` error
 - The container returns a `Could not resolve host` error