git publisher with, hopfully, correct branchName Variable

Jenkinsfile

@@ -60,17 +60,18 @@ pipeline {
 
         success {
 
-            if ( (env.BRANCH_NAME).startsWith('pr-') ) {
+            script {
+                if ({env.BRANCH_NAME}.startsWith('pr-')) {
 
 //                git url: "git@gogs.informatik.hs-fulda.de:SteffenN/Multi-Chess.git",
 //                        credentialsId: 'jenkins_ssh_key',
 //                        branch: (env.BRANCH_NAME)
 
-                sh "git merge '${env.BRANCH_NAME}'"
-                sh "git commit -am 'Merged ${env.BRANCH_NAME} branch to master'"
-                sh "git push origin master"
+                    sh "git merge '${env.BRANCH_NAME}'"
+                    sh "git commit -am 'Merged ${env.BRANCH_NAME} branch to master'"
+                    sh "git push origin master"
+                }
             }
-
             office365ConnectorSend color: 'good',
                     message: "Build ${currentBuild.fullDisplayName} completed *successfully* (<${BUILD_URL}>).\n\n\n${CUSTOM_SCM_INFO}",
                     webhookUrl: "https://outlook.office.com/webhook/97618564-835e-438e-a2a7-a77b21331e1e@22877e52-e9fd-410d-91a3-817d8ab89d63/JenkinsCI/fa736de2175649a891c2957f00532027/87d23462-1d0c-4378-b4e0-05c7d5546a25"