Fix sort order string formatting

app/src/main/java/com/todoroo/astrid/core/SortHelper.java

@@ -19,6 +19,8 @@ import com.todoroo.astrid.data.Task;
 
 import org.tasks.preferences.QueryPreferences;
 
+import java.util.Locale;
+
 /**
  * Helpers for sorting a list of tasks
  *
@@ -39,7 +41,7 @@ public class SortHelper {
   public static final long APPLE_EPOCH = 978307200000L; // 1/1/2001 GMT
   @SuppressLint("DefaultLocale")
   public static final String CALDAV_ORDER_COLUMN =
-      String.format("IFNULL(tasks.`order`, (tasks.created - %d) / 1000)", APPLE_EPOCH);
+      String.format(Locale.US, "IFNULL(tasks.`order`, (tasks.created - %d) / 1000)", APPLE_EPOCH);
 
   private static final String ADJUSTED_DUE_DATE =
       "(CASE WHEN (dueDate / 1000) % 60 > 0 THEN dueDate ELSE (dueDate + 43140000) END)";