vici: Fix README example encoding element type values, off by one

While we fixed the wrong values in the description with d39e04b5, the example
values are still off by one.

Fixes #828.

src/libcharon/plugins/vici/README.md

@@ -145,25 +145,25 @@ the following C array:
 
 	char msg[] = {
 		/* key1 = value1 */
-		2, 4,'k','e','y','1', 0,6,'v','a','l','u','e','1',
+		3, 4,'k','e','y','1', 0,6,'v','a','l','u','e','1',
 		/* section1 */
-		0, 8,'s','e','c','t','i','o','n','1',
+		1, 8,'s','e','c','t','i','o','n','1',
 		/* sub-section */
-		0, 11,'s','u','b','-','s','e','c','t','i','o','n',
+		1, 11,'s','u','b','-','s','e','c','t','i','o','n',
 		/* key2 = value2 */
-		2, 4,'k','e','y','2', 0,6,'v','a','l','u','e','2',
+		3, 4,'k','e','y','2', 0,6,'v','a','l','u','e','2',
 		/* sub-section end */
-		1,
+		2,
 		/* list1 */
-		3, 5, 'l','i','s','t','1',
+		4, 5, 'l','i','s','t','1',
 		/* item1 */
-		4, 0,5,'i','t','e','m','1',
+		5, 0,5,'i','t','e','m','1',
 		/* item2 */
-		4, 0,5,'i','t','e','m','2',
+		5, 0,5,'i','t','e','m','2',
 		/* list1 end */
-		5,
+		6,
 		/* section1 end */
-		1,
+		2,
 	};
 
 ## Client-initiated commands ##