fix(stacks): Remove unused functions in create stack controller [EE-1139] (#5401)

app/portainer/views/stacks/create/createStackController.js

@@ -68,14 +68,6 @@ angular
 
     $scope.onChangeFormValues = onChangeFormValues;
 
-    $scope.addEnvironmentVariable = function () {
-      $scope.formValues.Env.push({ name: '', value: '' });
-    };
-
-    $scope.removeEnvironmentVariable = function (index) {
-      $scope.formValues.Env.splice(index, 1);
-    };
-
     $scope.addAdditionalFiles = function () {
       $scope.formValues.AdditionalFiles.push('');
     };