fix ListFind test (#2436)

Author: amylizzle

Content.Tests/DMProject/Tests/List/ListFind.dm

@@ -12,7 +12,7 @@
 	ASSERT(L.Find("b", 3, 0) == 0)
 
 	ASSERT(L.Find("b", 1, 1) == 0)
-	ASSERT(L.Find("b", 1, 2) == 2)
+	ASSERT(L.Find("b", 1, 2) == 0)
 	ASSERT(L.Find("b", 1, 3) == 2)
 
 	ASSERT(L.Find("b", new /datum) == 2)

OpenDreamRuntime/Objects/Types/DreamList.cs

@@ -221,7 +221,7 @@ public virtual bool ContainsKey(DreamValue value) {
     public virtual int FindValue(DreamValue value, int start = 1, int end = 0) {
         if (end == 0 || end > _values.Count) end = _values.Count;
 
-        for (int i = start; i <= end; i++) {
+        for (int i = start; i < end; i++) {
             if (_values[i - 1].Equals(value)) return i;
         }