Fix addon release Jenkins Job

09:41:19 groovy.lang.MissingPropertyException: No such property: mslackColor for class: groovy.lang.Binding*09:41:19* at groovy.lang.Binding.getVariable(Binding.java:63)09:41:19 at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:270)09:41:19 at org.kohsuke.groovy.sandbox.impl.Checker$7.call(Checker.java:353)09:41:19 at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:357)09:41:19 at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:333)09:41:19 at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:333)09:41:19 at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:333)09:41:19 at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.getProperty(SandboxInvoker.java:29)09:41:19 at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)09:41:19 at WorkflowScript.run(WorkflowScript:154)09:41:19 at __cps.transform__(Native Method)09:41:19 at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:74)09:41:19 at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)09:41:19 at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:66)09:41:19 at sun.reflect.GeneratedMethodAccessor241.invoke(Unknown Source)09:41:19 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)09:41:19 at java.lang.reflect.Method.invoke(Method.java:498)09:41:19 at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)09:41:19 at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)09:41:19 at com.cloudbees.groovy.cps.Next.step(Next.java:83)09:41:19 at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)09:41:19 at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)09:41:19 at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:129)09:41:19 at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:268)09:41:19 at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)09:41:19 at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)09:41:19 at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:51)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:185)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:400)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)09:41:19 at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)09:41:19 at java.util.concurrent.FutureTask.run(FutureTask.java:266)09:41:19 at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:136)09:41:19 at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)09:41:19 at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)09:41:19 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)09:41:19 at java.util.concurrent.FutureTask.run(FutureTask.java:266)09:41:19 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)09:41:19 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)09:41:19 at java.lang.Thread.run(Thread.java:748)09:41:19 Finished: FAILURE