Corrected typo on deploying to AWS section

Author: Benjamin

section9/lectures/135_want_to_deploy_to_aws/commands.md

@@ -1,5 +1,5 @@
 ## Deploy to AWS
-If deploying on AWS, after installing Ubuntu 16.04, make sure to install libpcre2 and libpcre3-dev by running the following commands:
+If deploying on AWS, after installing Ubuntu 16.04, make sure to install libpcre3 and libpcre3-dev by running the following commands:
 
 ```bash
 sudo apt-get install libpcre3 libpcre3-dev