poky.ent: Updated release month variable to "June 2018"

Preparation for a 2.3.4 (Pyro) release.

(From yocto-docs rev: 834733897e900da254a607527492de218d89c28f)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/poky.ent

@@ -3,7 +3,7 @@
 <!ENTITY DISTRO_NAME_NO_CAP "pyro">
 <!ENTITY DISTRO_NAME "Pyro">
 <!ENTITY YOCTO_DOC_VERSION "2.3.4">
-<!ENTITY REL_MONTH_YEAR "May 2018">
+<!ENTITY REL_MONTH_YEAR "June 2018">
 <!ENTITY POKYVERSION "18.0.4">
 <!ENTITY POKYVERSION_COMPRESSED "1804">
 <!ENTITY YOCTO_POKY "poky-&DISTRO_NAME_NO_CAP;-&POKYVERSION;">