Update install.md (#492)

update and adding session dependancie

Author: lhirlimann

docs/install.md

@@ -17,7 +17,7 @@ Flarum 2.0 is currently in beta. It is not ready for production use.
 Before you install Flarum, it's important to check that your server meets the requirements. To run Flarum, you will need:
 
 * **Apache** (with mod\_rewrite enabled) or **Nginx**
-* **PHP 8.2+** with the following extensions: curl, dom, fileinfo, gd, json, mbstring, openssl, pdo\_mysql, tokenizer, zip
+* **PHP 8.2+** with the following extensions: curl, dom, fileinfo, gd, json, mbstring, openssl, pdo\_mysql, tokenizer, zip, session
 * **One of the following databases**:
   * MySQL 5.7+ / 8.0.30+
   * MariaDB 10.3+