minor fix

Jenkinsfile

@@ -9,6 +9,7 @@ pipeline {
         // Replace with your image name
         IMAGE_NAME = 'oh-service'
         // Variable for Git commit hash
+        GIT_COMMIT_HASH = ''
     }
     
     stages {
@@ -35,7 +36,7 @@ pipeline {
             steps {
                 script {
                     // Build with commit hash tag
-                    APP_GIT_HASH = sh(script: 'git rev-parse --short HEAD', returnStdout: true).trim()
+                    GIT_COMMIT_HASH = sh(script: 'git rev-parse --short HEAD', returnStdout: true).trim()
                     sh '''
                         docker build -t ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:latest .
                         docker tag ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:latest ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:${APP_GIT_HASH}
@@ -46,7 +47,7 @@ pipeline {
         
         stage('Push to Docker Hub') {
             steps {
-                APP_GIT_HASH = sh(script: 'git rev-parse --short HEAD', returnStdout: true).trim()
+                GIT_COMMIT_HASH = sh(script: 'git rev-parse --short HEAD', returnStdout: true).trim()
                 sh '''
                     # Push both tags
                     docker push ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:${APP_GIT_HASH}