Fix exportlang command

It was failing when the output directory already existed

(cherry picked from commit cf8b7b2)

src/main/java/betterquesting/commands/admin/QuestCommandDefaults.java

@@ -491,7 +491,7 @@ public static void exportLang(@Nullable ICommandSender sender, @Nullable String
         QuestLineDatabase.INSTANCE.values()
                 .forEach(questLine -> questOccurrenceCount.addAll(questLine.keySet()));
 
-        if (!dataDir.mkdirs()) {
+        if (!dataDir.exists() && !dataDir.mkdirs()) {
             QuestingAPI.getLogger().log(Level.ERROR, "Failed to create directory\n{}", dataDir);
             sendChatMessage(sender, "betterquesting.cmd.error");
             return;