package/docker-cli: bump version to 18.09.6

Additional post-18.09.5 fixes:

Builder:
- Fixed COPY and ADD with multiple <src> to not invalidate cache if
  DOCKER_BUILDKIT=1.moby/moby#38964

Networking:
- Cleaned up the cluster provider when the agent is closed. docker/libnetwork#2354
- Windows: Now selects a random host port if the user does not specify a
  host port.  docker/libnetwork#2369
- --service-cluster-ip-range is now configurable for UCP install.
  docker/orca#10263

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/docker-cli/docker-cli.hash

@@ -1,3 +1,3 @@
 # Locally calculated
-sha256	dfed7e3b14643101e6d3746e722cbe8294dcf078c5405f3fb78bc38c7c17f0b1  docker-cli-v18.09.5.tar.gz
+sha256	02bcb73dde1c9542fa65c8b87078aaa1b01b0dbdd62346637bcf0999a2a0909f  docker-cli-v18.09.6.tar.gz
 sha256	2d81ea060825006fc8f3fe28aa5dc0ffeb80faf325b612c955229157b8c10dc0  LICENSE

package/docker-cli/docker-cli.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-DOCKER_CLI_VERSION = v18.09.5
+DOCKER_CLI_VERSION = v18.09.6
 DOCKER_CLI_SITE = $(call github,docker,cli,$(DOCKER_CLI_VERSION))
 DOCKER_CLI_WORKSPACE = gopath