Update link to the ABI compatibility report

Author: azat

index.html

@@ -131,7 +131,7 @@ <h3>Documentation</h3>
 <br>
 ABI/API compatibility report:
 <a href="https://abi-laboratory.pro/index.php?view=timeline&l=libevent">releases</a>
-<a href="/abi">master</a>
+<a href="/abi/timeline/libevent/">master</a>
 <br>
 What's new in:
 <a href="https://raw.githubusercontent.com/libevent/libevent/patches-2.0/whatsnew-2.0.txt">2.0.x-stable</a>&ensp;