Fix EconomyTransaction NPE

Author: Ghost-chu

src/main/java/org/maxgamer/quickshop/api/economy/EconomyTransaction.java

@@ -48,6 +48,7 @@ public class EconomyTransaction {
     private final EconomyCore core;
     private final double actualAmount;
     private final double tax;
+    @Nullable
     private final Trader taxer;
     private final boolean allowLoan;
     private final boolean tryingFixBalanceInsufficient;
@@ -266,7 +267,7 @@ default boolean onCommit(@NotNull EconomyTransaction economyTransaction) {
          */
         default void onSuccess(@NotNull EconomyTransaction economyTransaction) {
             Util.debugLog("Transaction succeed.");
-            QuickShop.getInstance().logEvent(new EconomyTransactionLog(true, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
+            QuickShop.getInstance().logEvent(new EconomyTransactionLog(true, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer() == null ? Util.getNilUniqueId() : economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
         }
 
         /**
@@ -278,7 +279,7 @@ default void onSuccess(@NotNull EconomyTransaction economyTransaction) {
          */
         default void onFailed(@NotNull EconomyTransaction economyTransaction) {
             Util.debugLog("Transaction failed: " + economyTransaction.getLastError() + ".");
-            QuickShop.getInstance().logEvent(new EconomyTransactionLog(false, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
+            QuickShop.getInstance().logEvent(new EconomyTransactionLog(false, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer() == null ? Util.getNilUniqueId() : economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
         }
 
         /**
@@ -290,7 +291,7 @@ default void onFailed(@NotNull EconomyTransaction economyTransaction) {
          */
         default void onTaxFailed(@NotNull EconomyTransaction economyTransaction) {
             Util.debugLog("Tax Transaction failed: " + economyTransaction.getLastError() + ".");
-            QuickShop.getInstance().logEvent(new EconomyTransactionLog(false, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
+            QuickShop.getInstance().logEvent(new EconomyTransactionLog(false, economyTransaction.getFrom(), economyTransaction.getTo(), economyTransaction.getCurrency(), economyTransaction.getTax(), economyTransaction.getTaxer() == null ? Util.getNilUniqueId() : economyTransaction.getTaxer().getUniqueId(), economyTransaction.getAmount(), economyTransaction.getLastError()));
         }
 
     }