Bug 1488033 follow-up: Fix the name of the CSS property

browser/themes/shared/incontentprefs/privacy.css

@@ -152,7 +152,7 @@
   -moz-context-properties: fill, stroke;
   fill: #d7b600;
   stroke: white;
-  inline-padding-start: 20px;
+  padding-inline-start: 20px;
 }
 
 .reject-trackers-warning-icon:-moz-locale-dir(rtl) {