fix NPE in sell command w/o ongoing req

Author: RecursiveG

src/main/java/cat/nyaa/HamsterEcoHelper/requisition/RequisitionCommands.java

@@ -70,14 +70,16 @@ public static void haltRequisition(CommandSender sender, Arguments args, Hamster
     public static void userSell(CommandSender sender, Arguments args, HamsterEcoHelper plugin) {
         Player p = asPlayer(sender);
         RequisitionInstance req = plugin.reqManager.getCurrentRequisition();
-        if (req.owner != null && req.owner.getUniqueId().equals(p.getUniqueId())) {
-            return;
-        }
         if (req == null) {
             msg(sender, "user.info.no_current_requisition");
             return;
         }
 
+        if (req.owner != null && req.owner.getUniqueId().equals(p.getUniqueId())) {
+            msg(sender, "user.req.sell_to_self");
+            return;
+        }
+
         int amount;
         if (args.length() == 1) {
             amount = Math.min(getItemInHand(sender).getAmount(), req.getAmountRemains());

src/main/resources/lang/en_US.yml

@@ -95,6 +95,7 @@ user:
     sold_out: "Requisition limit reached. Requisition finished."
     sold_amount_0: "Player %s has sold %d "
     sold_amount_1: "! %d remains."
+    sell_to_self: "You cannot sell to yourself"
   market:
     title: "[Market]"
     mailbox: "[Mailbox]"