Add comment about Dockerfile source

tesuji · tesuji · commit cbe4c1a80062 · 2019-04-11T18:47:59.000+07:00
diff --git a/ci/docker/x86_64-unknown-linux-gnu/Dockerfile b/ci/docker/x86_64-unknown-linux-gnu/Dockerfile
@@ -1,3 +1,4 @@
+# Source from https://github.com/rust-lang-deprecated/rust-buildbot/blob/master/slaves/dist/Dockerfile
 FROM alexcrichton/rust-slave-dist:2015-10-20b
 USER root
 

Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,4 @@`
	`1`	`+# Source from https://github.com/rust-lang-deprecated/rust-buildbot/blob/master/slaves/dist/Dockerfile`
`1`	`2`	`FROM alexcrichton/rust-slave-dist:2015-10-20b`
`2`	`3`	`USER root`
`3`	`4`