Fix date in CHANGES

The release scripts expect to see the date "xx XXX xxxx" in CHANGES. At
some point the year got changed from xxxx to 2016. This changes it back.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

CHANGES

@@ -2,7 +2,7 @@
  OpenSSL CHANGES
  _______________
 
- Changes between 1.0.2h and 1.1.0  [xx XXX 2016]
+ Changes between 1.0.2h and 1.1.0  [xx XXX xxxx]
 
   *) The method for finding the storage location for the Windows RAND seed file
      has changed. First we check %RANDFILE%. If that is not set then we check