update BUILD files

vendor/github.com/docker/go-connections/nat/BUILD

@@ -7,6 +7,7 @@ go_library(
         "parse.go",
         "sort.go",
     ],
+    importpath = "github.com/docker/go-connections/nat",
     visibility = ["//visibility:public"],
 )
 

vendor/github.com/docker/go-connections/sockets/BUILD

@@ -15,6 +15,7 @@ go_library(
         ],
         "//conditions:default": [],
     }),
+    importpath = "github.com/docker/go-connections/sockets",
     visibility = ["//visibility:public"],
     deps = [
         "//vendor/golang.org/x/net/proxy:go_default_library",

vendor/github.com/docker/go-connections/tlsconfig/BUILD

@@ -9,6 +9,7 @@ go_library(
         "config_client_ciphers.go",
         "config_legacy_client_ciphers.go",
     ],
+    importpath = "github.com/docker/go-connections/tlsconfig",
     visibility = ["//visibility:public"],
     deps = ["//vendor/github.com/pkg/errors:go_default_library"],
 )