Do not insert explicit visibility modifier if it's default

idea/testData/quickfix/modifiers/visibilityModiferOverrideJavaRuntime.kt.after

@@ -1,6 +1,6 @@
 // "Change visibility modifier" "true"
 abstract class C : ClassLoader() {
-    <caret>protected override fun findClass(var1: String): Class<*> {
+    <caret>override fun findClass(var1: String): Class<*> {
         throw ClassNotFoundException(var1)
     }
 }