Added Jenkins multiarch docker build

Jenkinsfile

@@ -1,18 +1,15 @@
 
 node {    
-      def app     
-      stage('Clone repository') {               
+      environment{
+            IMAGENAME = "agreiner/advancedmqttbridge"
+      }
 
+      stage('Clone repository') {               
             checkout scm    
       }     
-      stage('Build image') {         
-       
-            app = docker.build("agreiner/advancedmqttbridge")    
-       }
-       stage('Push image') {
-                                                  docker.withRegistry('https://reg.greinet.com', 'docker_registry_jenkins') {            
-       app.push("1.${env.BUILD_NUMBER}")            
-       app.push("latest")        
-              }    
-           }
+      stage('Build multiarch image') {
+            sh """
+                  docker buildx build -t reg.greinet.com/agreiner/advancedmqttbridge:latest --platform linux/amd64,linux/arm64,linux/ppc64le --push .
+            """
        }
+}