Update reply-url.md

As part of internal ADO Identity item - https://identitydivision.visualstudio.com/Engineering/_workitems/edit/2240922 
We need this restriction to be clearly stated in public documentation.

Author: jsoveral

articles/active-directory/develop/reply-url.md

@@ -35,6 +35,8 @@ The Azure Active Directory (Azure AD) application model specifies these restrict
     * `https://contoso.com/abc` is returned as `https://contoso.com/abc`
     * `https://contoso.com/abc/response-oidc` is returned as `https://contoso.com/abc/response-oidc`
 
+* Redirect URIs do not support special characters - `! $ ' ( ) , ;`
+
 ## Maximum number of redirect URIs
 
 This table shows the maximum number of redirect URIs you can add to an app registration in the Microsoft identity platform.