This commit is a fix for Bug#19880969 (CLUB FOR 7.1, LINUX-RELEASE, 345 WARNINGS IN BUILD). The fix suppresses these warnings, so that the corresponding square in club becomes green rather than red.

It would have been possible to get rid of the warnings by changing the concerned source code. We chose not to do so because:
- None of the warnings pinpoint real errors.
- This issue does not justify modifiying the 5.1. server code at this point. The main goal was to make it easy to spot any *new* errors or warnings being introduced.