fix another sh

JenkinsDatastatsDockerhub

@@ -32,8 +32,7 @@ pipeline {
         }
         stage('Stats in docker') {
             steps {
-                // run python3 main.py inside docker created from karolcyganik/ium image
-                sh "docker run -v $(pwd):/app karolcyganik/ium python3 main.py"
+                sh "docker run -v ${PWD}:/app karolcyganik/ium python3 main.py"
             }
         }
     }