JS backend: format builder.kt according to code style.

(cherry picked from commit 7c2a2cd)

js/js.translator/testFiles/webDemoExamples2/cases/builder.kt

@@ -74,7 +74,7 @@ abstract class Tag(val name : String) : Element {
     override fun render(builder: StringBuilder, indent: String) {
         builder.append("$indent<$name${renderAttributes()}>\n")
         for (c in children) {
-    c?.render(builder, indent + "  ")
+            c.render(builder, indent + "  ")
         }
         builder.append("$indent</$name>\n")
     }