Stop "give pc" quest action rearming

This quest action could rearm and attempt to give letter multiple times, resulting in an exception loop.
Set "give pc" allowRearm to false. This will prevent issue in future saves and affected saves will self-correct in one quest tick.
Downgraded duplicate item exception to a LogError(). Saves affected by this issue will see error in log and any message popups on next tick, then quest action will switch off properly.

Assets/Scripts/Game/Items/ItemCollection.cs

@@ -226,9 +226,12 @@ public void AddItem(DaggerfallUnityItem item, AddPosition position = AddPosition
             }
             else
             {
-                // Check duplicate key
+                // Log and exit if duplicate key found
                 if (items.Contains(item.UID))
-                    throw new Exception("AddItem() encountered a duplicate item UID for " + item.LongName);
+                {
+                    UnityEngine.Debug.LogError("AddItem() encountered a duplicate item UID for " + item.LongName);
+                    return;
+                }
 
                 // Add the item
                 switch (position)

Assets/Scripts/Game/Questing/Actions/GivePc.cs

@@ -1,4 +1,4 @@
-// Project:         Daggerfall Tools For Unity
+// Project:         Daggerfall Tools For Unity
 // Copyright:       Copyright (C) 2009-2018 Daggerfall Workshop
 // Web Site:        http://www.dfworkshop.net
 // License:         MIT License (http://www.opensource.org/licenses/mit-license.php)
@@ -45,6 +45,7 @@ public override string Pattern
         public GivePc(Quest parentQuest)
             : base(parentQuest)
         {
+            allowRearm = false;
         }
 
         public override IQuestAction CreateNew(string source, Quest parentQuest)