Update sharepoint-2019-support.md

`npm install @microsoft/[email protected] --global` instead of 1.10.0

Author: AJIXuMuK

docs/spfx/sharepoint-2019-support.md

@@ -49,7 +49,7 @@ Microsoft recommends using the most recent version of the Yeoman generator for t
     ```console
     npm install [email protected] --global
     npm install [email protected] --global
-    npm install @microsoft/generator-sharepoint@1.10.0 --global
+    npm install @microsoft/generator-sharepoint@1.4.1 --global
     ```
 
 For more information, see [SharePoint Framework development tools and libraries compatibility](compatibility.md).