Reenable Sonarcloud check in PR's

[smoya]

As you can check here, I had to manually remove the Sonarcloud check for master branch.
It seems there is some random issue. More info and possible next steps here: asyncapi/.github#306

[smoya]

Reenabled.

It seems all i needed to do is to remove the required check from master branch in GH branch protection rules. Then Sonarcloud added automatically a new check into the PR's (seems like different, this one has a logo of Sonarcloud?).
Then, adding back the check in branch protection like in the following screenshot (notice that the source now says Sonarcloud, where previously said "any source").