[Swift] Update the Swift toolchain to 4.2.3

library/swift

@@ -7,8 +7,8 @@ Maintainers: Ted Kremenek <[email protected]> (@tkremenek),
 GitRepo: https://github.com/apple/swift-docker.git
 
 
-Tags: 4.2.2, 4.2.1, 4.2, 4, latest
-GitCommit: c5dd5e013de66da930cf1b9804797dbae11e8f9c
+Tags: 4.2.3, 4.2.2, 4.2.1, 4.2, 4, latest
+GitCommit: 75dde01ef86e98437b1206c6a58d0428dfb345a4
 Directory: 4.2/ubuntu/16.04
 
 Tags: 4.1.3, 4.1