Update CHANGES (releng for 1.5).
Update CHANGES (releng for 1.5).

Change-Id: I41bfbf49e64787ce50628bb14a6f7eeac713bbc4
Signed-off-by: Piotr Sikora <321b1a11e6b8c7ca12f1b0b438664e52a48b555e@frickle.com>

ainoya/ngx_cache_purge,ainoya/ngx_cache_purge,FRiCKLE/ngx_cache_purge,FRiCKLE/ngx_cache_purge,lilien1010/ngx_cache_purge,lilien1010/ngx_cache_purge