NO-ISSUE: fix setup-branch cleanWs problem

[jstastny-cz]

Quick fix to prevent the cleanWs asynchronously deleting things for the following steps on the go.

[kie-ci3]

PR job #18 was: FAILURE
Possible explanation: Pipeline failure or project build failure

Please look here: https://ci-builds.apache.org/job/KIE/job/kogito/job/main/job/pullrequest/job/kogito-images.build-and-test/18/display/redirect
See console log:

Console Logs

From https://github.com/jstastny-cz/kogito-images
* branch fix-setup-branch -> FETCH_HEAD
hint: You have divergent branches and need to specify how to reconcile them.
hint: You can do so by running one of the following commands sometime before
hint: your next pull:
hint:
hint: git config pull.rebase false # merge (the default strategy)
hint: git config pull.rebase true # rebase
hint: git config pull.ff only # fast-forward only
hint:
hint: You can replace "git config" with "git config --global" to set a default
hint: preference for all repositories. You can also pass --rebase, --no-rebase,
hint: or --ff-only on the command line to override the configured default per
hint: invocation.
fatal: Need to specify how to reconcile divergent branches.
[Pipeline] }
[Pipeline] // withCredentials
[Pipeline] echo

-------------------------------------------------------------
[ERROR] Can't merge source into Target. Please rebase PR branch.
-------------------------------------------------------------
Source: git://github.com/jstastny-cz/kogito-images fix-setup-branch
Target: e2a603c [10.0.x] Update version to 10.0.999-snapshot
-------------------------------------------------------------

[Pipeline] }
[Pipeline] // dir
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Validate CeKit Image and Modules descriptors)
Stage "Validate CeKit Image and Modules descriptors" skipped due to earlier failure(s)
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Build & Test Images)
Stage "Build & Test Images" skipped due to earlier failure(s)
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Declarative: Post Actions)
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ wget --no-check-certificate -qO - 'https://ci-builds.apache.org/job/KIE/job/kogito/job/main/job/pullrequest/job/kogito-images.build-and-test/18/api/json?depth=0'
[Pipeline] readJSON
[Pipeline] sh