minor #19231 Update flex_private_recipes.rst (ioanok)

This PR was submitted for the 7.0 branch but it was merged into the 5.4 branch instead.

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Update flex_private_recipes.rst

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a0ede91 Update flex_private_recipes.rst

Author: OskarStark

setup/flex_private_recipes.rst

@@ -224,7 +224,7 @@ computer, and execute the following command:
 
 .. code-block:: terminal
 
-    $ composer config --global --auth gitlab-oauth.gitlab.com [token]
+    $ composer config --global --auth gitlab-token.gitlab.com [token]
 
 Replace ``[token]`` with the value of your Gitlab personal access token.