Update stack-installation.md

Author: qiaofeng1227

docs/stack-installation.md

@@ -5,7 +5,7 @@ If you have completed the CouchDB deployment on Cloud Platform, the following st
 ## Preparation
 
 1. Get the **Internet IP** on your Cloud Platform
-2. Check you **[Inbound of Security Group Rule](https://support.websoft9.com/docs/faq/tech-instance.html)** of Cloud Console to ensure the TCP:8161 is allowed
+2. Check you **[Inbound of Security Group Rule](https://support.websoft9.com/docs/faq/tech-instance.html)** of Cloud Console to ensure the TCP:5984 is allowed
 3. Make a domain resolution on your DNS Console if you want to use domain for CouchDB
 
 ## CouchDB Installation Wizard
@@ -27,4 +27,4 @@ If you have completed the CouchDB deployment on Cloud Platform, the following st
 
 Your TCP:80 of Security Group Rules is not allowed so there no response from Chrome or Firefox
 
-#### CouchDB service can't start? 
+#### CouchDB service can't start?