Fix potential NPE on exception path

Findbug reported NP_NULL_ON_SOME_PATH_EXCEPTION, Priority: Normal
correct help text of Label field => can be a Label Expression
[FIXED JENKINS-16918] Use HTTP 405 when POST is required.
Random failure.
https://jenkins.ci.cloudbees.com/job/core/job/jenkins_main_trunk/1065/testReport/junit/hudson.model/ProjectTest/testPoll/
Merge pull request #900 from mpapo/JENKINS-19091

correct help text of Label field => can be a Label Expression
updated changelog for JENKINS-19091
Merge branch 'master' of github.com:jenkinsci/jenkins

Conflicts:
	changelog.html
Fixing a few warnings.
use guice from google rather than a fork
use Guice from Google rather than a fork
Windows::killRecursively() invokes process killers after completion.
Resolves https://issues.jenkins-ci.org/browse/JENKINS-19156

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
Merge branch 'jenkins_19156_windows_processkiller' of https://github.com/synopsys-arc-oss/jenkins into pr903
Added changelog for PR #903
last aether version 0.9.0.M3
fix new artifactId for wagon aether
[JENKINS-19082] Fix ListView includeRegex
Merge pull request #905 from Vlatombe/fixIncludeRegexListView

[JENKINS-19082] Fix ListView includeRegex
Merge pull request #899 from mvach/potential-npe

Fix potential NPE on exception path
Unchecked warning.
Comment.