Prevent crash

app/src/main/java/eu/faircode/email/Core.java

@@ -1675,11 +1675,10 @@ class Core {
             if (light)
                 builder.setLights(Color.GREEN, 1000, 1000);
 
-            if (sound == null) {
-                Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
+            Uri uri = (sound == null ? null : Uri.parse(sound));
+            if (uri == null || "file".equals(uri.getScheme()))
+                uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
             builder.setSound(uri);
-            } else
-                builder.setSound(Uri.parse(sound));
 
             builder.setOnlyAlertOnce(true);
         } else

app/src/main/java/eu/faircode/email/FragmentOptions.java

@@ -828,6 +828,8 @@ public class FragmentOptions extends FragmentBase implements SharedPreferences.O
             if (resultCode == RESULT_OK) {
                 Uri uri = data.getParcelableExtra(RingtoneManager.EXTRA_RINGTONE_PICKED_URI);
                 Log.i("Selected ringtone=" + uri);
+                if (uri != null && "file".equals(uri.getScheme()))
+                    uri = null;
 
                 SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
                 if (uri == null)