fix: che callback url (#3129)

Signed-off-by: Anatolii Bazko <abazko@redhat.com>

Author: tolusha

modules/install/pages/proc_installing-che-on-openshift-with-keycloak-as-oidc.adoc

@@ -41,9 +41,8 @@ NOTE: Run the following command to obtain the `{prod}` redirect URL:
 [source,bash,subs="+quotes,+attributes"]
 ----
 echo "$(
-  {orch-cli} get checluster {prod-checluster} \
-    -n {prod-namespace} \
-    -o jsonpath='{.status.cheURL}'
+  oc whoami --show-console |
+  sed 's|console-openshift-console|{prod-id}|g'
 )/oauth/callback"
 ----