Update OSDK mirror site URL for 4.8+

Author: adellape

modules/osdk-installing-cli-linux-macos.adoc

@@ -3,7 +3,7 @@
 // * cli_reference/osdk/cli-osdk-install.adoc
 // * operators/operator_sdk/osdk-installing-cli.adoc
 
-:ocp_ver: latest
+:ocp_ver: 4.8.4
 :osdk_ver: v1.8.0
 
 [id="osdk-installing-cli-linux-macos_{context}"]