Tweak docker compose setup (#11785)

* fix stray dockerhost mention

* fix stray whitespace

* fix missing mattermost-redix cleanup in clean-old-docker

* absolute path to docker-compose, plus simpler ldap initialization

* allow ldapadd to fail on CI

app/plugin_test.go

@@ -336,7 +336,7 @@ func TestPluginSync(t *testing.T) {
 			func(cfg *model.Config) {
 				s3Host := os.Getenv("CI_MINIO_HOST")
 				if s3Host == "" {
-					s3Host = "dockerhost"
+					s3Host = "localhost"
 				}
 
 				s3Port := os.Getenv("CI_MINIO_PORT")