Revert "Fix for Issue TheAlgorithms#773. Deleting an element that doesn't exist causes NPE"

This reverts commit 7eb0785.

Author: abhijaykumar

DataStructures/Lists/DoublyLinkedList.java

@@ -116,13 +116,8 @@ public Link deleteTail() {
     public void delete(int x) {
         Link current = head;
 
-        while (current.value != x) {// Find the position to delete
-            if (current != tail) {
-                current = current.next;
-            } else {// If we reach the tail and the element is still not found
-                throw new RuntimeException("The element to be deleted does not exist!");
-            }
-        }
+        while (current.value != x) // Find the position to delete
+            current = current.next;
 
         if (current == head)
             deleteHead();