index.html:fix dead link

index.html

@@ -19,8 +19,8 @@ Current release: <a href="json-c-0.13.1/doc/html/index.html">json-c-0.13.1</a>
 <a href="json-c-0.13.1/doc/html/json__tokener_8h.html">json_tokener.h</a>
 
 You can also look at the tests in <a href="https://github.com/json-c/json-c/blob/json-c-0.13.1/tests/">the tests directory</a> for some examples.<br>
-One of the simplest examples is 
-<a href="https://github.com/json-c/json-c/blob/json-c-0.13.1/tests/test2.c">test2.c</a>.
+One of the simplest examples is
+<a href="https://github.com/json-c/json-c/blob/json-c-0.13.1-20180305/tests/test2.c">test2.c</a>.
 
 
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