Fix #244 textarea padding in variable values editor

src/app/components/dialog-edit-param-values/dialog-edit-param-values.component.scss

@@ -5,6 +5,7 @@ mat-form-field {
     textarea {
         font-size: .8em;
         max-height: 100px;
+        padding: 0;
     }
 
     mat-error {