fix back button for feed on main page

app/src/main/java/org/schabi/newpipe/fragments/list/BaseListFragment.java

@@ -187,7 +187,11 @@ public abstract class BaseListFragment<I, N> extends BaseStateFragment<I> implem
         ActionBar supportActionBar = activity.getSupportActionBar();
         if (supportActionBar != null) {
             supportActionBar.setDisplayShowTitleEnabled(true);
-            supportActionBar.setDisplayHomeAsUpEnabled(true);
+            if(useAsFrontPage) {
+                supportActionBar.setDisplayHomeAsUpEnabled(false);
+            } else {
+                supportActionBar.setDisplayHomeAsUpEnabled(true);
+            }
         }
     }