update changelog for release

Author: ecrist

ChangeLog

@@ -1,12 +1,13 @@
 Easy-RSA 3 ChangeLog
 
-3.1.3 (ETA: 2023-10-13)
+3.1.3 (ETA: 2023-05-19)
    * build-ca: Replace password temp-files with file-descriptors (#955)
    * Replace --fix-offset with --startdate, --enddate (#918)
    * Introduce option -S|--silent-ssl: Silence SSL output (#913)
    * Only create a random serial number file when expected (#896)
    * Always verify SSL lib, for all commands (#877)
    * Option --fix-offset: Adjust off-by-one day (#847) Superseded (#918)
+   * Update OpenSSL to v3.0.8
 
 3.1.2 (2023-01-13)
    * build-full: Always enable inline file creation (#834)