Don't finish the activity in second level of SettingsActivity

app/src/main/java/com/hippo/ehviewer/ui/SettingsActivity.java

@@ -84,7 +84,7 @@ public final class SettingsActivity extends EhPreferenceActivity {
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case android.R.id.home:
-                finish();
+                onBackPressed();
                 return true;
             default:
                 return super.onOptionsItemSelected(item);