PUZZLES.md page updated

PUZZLES.md

@@ -35,7 +35,7 @@ There are 8 active puzzles (59 total):
 &nbsp;&nbsp;&nbsp;&nbsp;[<del>445</del>](https://github.com/yegor256/takes/issues/445) [`?`](../master/?)<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<del>445-5323c196</del> [`RqHref.java:83-86`](../master/src/main/java/org/takes/rq/RqHref.java#L83-L86)<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;[<del>490</del>](https://github.com/yegor256/takes/issues/490) [`?`](../master/?)<br/>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[#508](https://github.com/yegor256/takes/issues/508):[<del>490-c74fee69</del>](https://github.com/yegor256/takes/issues/508) [`RqHeaders.java:93-98`](../master/src/main/java/org/takes/rq/RqHeaders.java#L93-L98)<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<del>490-c74fee69</del> [`RqHeaders.java:93-98`](../master/src/main/java/org/takes/rq/RqHeaders.java#L93-L98)<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;[#519](https://github.com/yegor256/takes/issues/519):[**306-b987400a**](https://github.com/yegor256/takes/issues/519) [`BkBasicTest.java:57-60`](../master/src/test/java/org/takes/http/BkBasicTest.java#L57-L60)<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;[<del>516</del>](https://github.com/yegor256/takes/issues/516) [`?`](../master/?)<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[#533](https://github.com/yegor256/takes/issues/533):[<del>516-c8aa6c8f</del>](https://github.com/yegor256/takes/issues/533) [`BkBasicTest.java:67-68`](../master/src/test/java/org/takes/http/BkBasicTest.java#L67-L68)<br/>