Update release date for 2.5.2

(cherry picked from commit 1e9a3f42ff49be788ac99e5f06a7984d1d0638cc)
HDFS-7425. NameNode block deletion logging uses incorrect appender. Contributed by Chris Nauroth.

(cherry picked from commit b8c094b0754099f13d668081b4afcf0644e325c3)
(cherry picked from commit 8d8eb8dcec94e92d94eedef883cdece8ba333087)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt