RFR: 8200586: Update JDK11 release date to 2018-09-25

[Abhijit Saha]

Release date for jdk11 seems incorrectly shown as '2018-09-18' while
it should be '2018-09-25'. Need to update the configuration accordingly.

Bug: https://bugs.openjdk.java.net/browse/JDK-8200586

Change:

--- a/make/autoconf/version-numbers
+++ b/make/autoconf/version-numbers
@@ -29,7 +29,7 @@
  DEFAULT_VERSION_INTERIM=0
  DEFAULT_VERSION_UPDATE=0
  DEFAULT_VERSION_PATCH=0
-DEFAULT_VERSION_DATE=2018-09-18
+DEFAULT_VERSION_DATE=2018-09-25
  DEFAULT_VERSION_CLASSFILE_MAJOR=55  # "`$EXPR $DEFAULT_VERSION_FEATURE 
+ 44`"
  DEFAULT_VERSION_CLASSFILE_MINOR=0
  DEFAULT_ACCEPTABLE_BOOT_VERSIONS="9 10 11"


Thanks,
Abhijit