add missing Changelog entry

Author: weltling

ChangeLog-7.php

@@ -19,6 +19,10 @@
   <li><?php bugfix(72400); ?> (Integer Overflow in addcslashes/addslashes).</li>
   <li><?php bugfix(72403); ?> (Integer Overflow in Length of String-typed ZVAL).</li>
 </ul></li>
+<li>Date:
+<ul>
+  <li><?php bugfix(63740); ?> (strtotime seems to use both sunday and monday as start of week).</li>
+</ul></li>
 <li>FPM:
 <ul>
   <li><?php bugfix(72308); ?> (fastcgi_finish_request and logging environment variables).</li>