upstream_contribution_process: Remove reference to old IP policy

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

contributing/upstream_contribution_process.rst

@@ -14,7 +14,7 @@ Contributing to Projects not Maintained by |main_project_name| Team
 Overview
 ********
 
-In order to comply with :ref:`Upstream first<sec-upstream>` rule and Open Source licenses requirements, |main_project_name| developers collaborate with several upstream projects to submit fixes, improvements, bug reports, problem investigation results etc. Contribution must be made in accordance with upstream project policy using the tooling upstream project prefers such as mailing list, github/gitlab pull/merge requests, etc.
+In order to comply with "upstream first" rule and Open Source licenses requirements, |main_project_name| developers collaborate with several upstream projects to submit fixes, improvements, bug reports, problem investigation results etc. Contribution must be made in accordance with upstream project policy using the tooling upstream project prefers such as mailing list, github/gitlab pull/merge requests, etc.
 
 .. _sec_upstream_contrib_signoff: