Fix incorrectly signed CrdsValues (bp #6696)

[mergify]

This is an automated backport of pull request #6696 done by Mergify.io

Cherry-pick of 568475e has failed:

On branch mergify/bp/v0.20/pr-6696
Your branch is up to date with 'origin/v0.20'.

You are currently cherry-picking commit 568475e2d.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:

	modified:   core/src/contact_info.rs
	modified:   core/src/crds.rs
	modified:   core/src/crds_gossip.rs
	modified:   core/src/crds_gossip_pull.rs
	modified:   core/src/crds_gossip_push.rs
	modified:   core/src/crds_value.rs
	modified:   core/tests/crds_gossip.rs

Unmerged paths:
  (use "git add <file>..." to mark resolution)

	both modified:   core/src/cluster_info.rs

To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

[codecov]

Codecov Report

Merging #6699 into v0.20 will increase coverage by 0.7%.
The diff coverage is 65.5%.

@@           Coverage Diff           @@
##           v0.20   #6699     +/-   ##
=======================================
+ Coverage     65%   65.7%   +0.7%     
=======================================
  Files        218     215      -3     
  Lines      49053   48516    -537     
=======================================
  Hits       31914   31914             
+ Misses     17139   16602    -537