update Fluentd for 1.18 test (#741)

Follow update of:

*
https://github.com/fluent/fluentd/tree/restart-without-downtime-test-for-1.18

Signed-off-by: Daijiro Fukuda <fukuda@clear-code.com>

Author: daipom

fluent-package/Gemfile.lock

@@ -9,8 +9,8 @@ GIT
 
 GIT
   remote: https://github.com/fluent/fluentd
-  revision: 759bb582a1d4a1b1d163197870669f7bee0aa148
-  ref: 759bb582a1d4a1b1d163197870669f7bee0aa148
+  revision: 4285c165b1c94d5622475564c4ab269a0cc125e1
+  ref: 4285c165b1c94d5622475564c4ab269a0cc125e1
   specs:
     fluentd (1.18.0)
       base64 (~> 0.2)

fluent-package/config.rb

@@ -7,7 +7,7 @@
 PACKAGE_DIR = "fluent"
 COMPAT_PACKAGE_DIR = COMPAT_SERVICE_NAME
 
-FLUENTD_REVISION = '759bb582a1d4a1b1d163197870669f7bee0aa148' # test no-downtime (TODO fix later)
+FLUENTD_REVISION = '4285c165b1c94d5622475564c4ab269a0cc125e1' # test no-downtime (TODO fix later)
 FLUENTD_LOCAL_GEM_REPO = "file://" + File.expand_path(File.join(__dir__, "local_gem_repo"))
 
 # https://github.com/jemalloc/jemalloc/releases