Protect initServerProviders() method

[jadelkhoury]

Description

Protect initServerProviders() method

Checklist

• [x] This PR adds an entry to the CHANGELOG. _See https://keepachangelog.com/en/1.0.0/ for instructions. Minor edits are exempt.
• [ ] This PR expects some manual changes to the generated code. The needed changes are detailed in the CHANGELOG entry.
• [x] This PR was tested with at least one code generation, resulting in a working OSLC server.
• [x] This PR does NOT break the user block code

[jadelkhoury]

once https://github.com/oslc-op/refimpl/pull/190 is approved, we can approve this PR.