Merge pull request #339 from thaJeztah/19.03_backport_fix_containerd_optional_docker_content_digest

[19.03 backport] vendor: containerd to 7c1e88399
Upstream-commit: 0b12b76c281fe1739d4ed778b0050243d0fff1e5
Component: engine

Author: thaJeztah

components/engine/vendor.conf

@@ -119,14 +119,14 @@ github.com/googleapis/gax-go                        317e0006254c44a0ac427cc52a0e
 google.golang.org/genproto                          694d95ba50e67b2e363f3483057db5d4910c18f9
 
 # containerd
-github.com/containerd/containerd                    3a3f0aac8819165839a41fee77a4f4ac8b103097
+github.com/containerd/containerd                    7c1e88399ec0b0b077121d9d5ad97e647b11c870
 github.com/containerd/fifo                          a9fb20d87448d386e6d50b1f2e1fa70dcf0de43c
 github.com/containerd/continuity                    aaeac12a7ffcd198ae25440a9dff125c2e2703a7
 github.com/containerd/cgroups                       4994991857f9b0ae8dc439551e8bebdbb4bf66c1
 github.com/containerd/console                       0650fd9eeb50bab4fc99dceb9f2e14cf58f36e7f
 github.com/containerd/go-runc                       7d11b49dc0769f6dbb0d1b19f3d48524d1bad9ad
 github.com/containerd/typeurl                       2a93cfde8c20b23de8eb84a5adbc234ddf7a9e8d
-github.com/containerd/ttrpc                         f02858b1457c5ca3aaec3a0803eb0d59f96e41d6
+github.com/containerd/ttrpc                         699c4e40d1e7416e08bf7019c7ce2e9beced4636
 github.com/gogo/googleapis                          d31c731455cb061f42baff3bda55bad0118b126b # v1.2.0
 
 # cluster