Sort .gitignore files using LC_COLLATE=C like core

Sort plugin's .gitignore files this way like Gerrit core's root
.gitignore; also used by other Gerrit plugin components:

$ LC_COLLATE=C sort .gitignore

Add blank lines between the natural .gitignore file sections, for sorted
lines readability purposes.

Sorting this way also allows for the redundant 'gerrit-2/bin' line to be
removed from the dockerised_local_env/.gitignore file.

Change-Id: I6504150453118e2c5d968126caff0922e436117b

.gitignore

diff --git a/.gitignore b/.gitignore
index 6b0bf05..4d4a78b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,13 +1,17 @@
+# LC_COLLATE=C sort
+
 .DS_Store
+/.apt_generated/
 /.classpath
+/.primary_build_tool
 /.project
 /.settings/
-/.primary_build_tool
+
 /bazel-bin
 /bazel-genfiles
+/bazel-multi-site
 /bazel-out
 /bazel-reviewers
 /bazel-testlogs
-/bazel-multi-site
+
 /eclipse-out/
-/.apt_generated/

dockerised_local_env/.gitignore

diff --git a/dockerised_local_env/.gitignore b/dockerised_local_env/.gitignore
index c88a11c..4eee0e8 100644
--- a/dockerised_local_env/.gitignore
+++ b/dockerised_local_env/.gitignore
@@ -1,25 +1,28 @@
-gerrit-1/plugins
-gerrit-1/db
-gerrit-1/git
-gerrit-1/logs
-gerrit-1/index
-gerrit-1/data
+# LC_COLLATE=C sort
+
 gerrit-1/bin
+gerrit-1/data
+gerrit-1/db
 gerrit-1/etc
-gerrit-1/tmp
+gerrit-1/git
+gerrit-1/index
 gerrit-1/lib
+gerrit-1/logs
+gerrit-1/plugins
 gerrit-1/ssh/known_hosts
-gerrit-2/plugins
-gerrit-2/db
-gerrit-2/git
-gerrit-2/logs
-gerrit-2/index
+gerrit-1/tmp
+
+gerrit-2/bin
 gerrit-2/data
-gerrit-2/bin
+gerrit-2/db
 gerrit-2/etc
-gerrit-2/tmp
+gerrit-2/git
+gerrit-2/index
 gerrit-2/lib
+gerrit-2/logs
+gerrit-2/plugins
 gerrit-2/ssh/known_hosts
-gerrit-2/bin
+gerrit-2/tmp
+
 syslog-sidecar/logs
 syslog-sidecar/socket