Revert "chore: Upgrade smallstep libs (#4307)"

This reverts commit f6d5ec2.

go.mod

@@ -17,19 +17,19 @@ require (
 	github.com/mholt/acmez v0.1.3
 	github.com/naoina/go-stringutil v0.1.0 // indirect
 	github.com/naoina/toml v0.1.1
-	github.com/prometheus/client_golang v1.11.0
-	github.com/smallstep/certificates v0.16.4
-	github.com/smallstep/cli v0.16.1
-	github.com/smallstep/nosql v0.3.8
+	github.com/prometheus/client_golang v1.10.1-0.20210603120351-253906201bda
+	github.com/smallstep/certificates v0.16.1
+	github.com/smallstep/cli v0.15.16
+	github.com/smallstep/nosql v0.3.7
 	github.com/smallstep/truststore v0.9.6
 	github.com/yuin/goldmark v1.3.8
 	github.com/yuin/goldmark-highlighting v0.0.0-20210516132338-9216f9c5aa01
 	go.uber.org/zap v1.17.0
-	golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e
-	golang.org/x/net v0.0.0-20210614182718-04defd469f4e
+	golang.org/x/crypto v0.0.0-20210513164829-c07d793c2f9a
+	golang.org/x/net v0.0.0-20210525063256-abc453219eb5
 	golang.org/x/term v0.0.0-20210503060354-a79de5458b56
-	google.golang.org/genproto v0.0.0-20210604141403-392c879c8b08
-	google.golang.org/protobuf v1.27.1
+	google.golang.org/genproto v0.0.0-20210602131652-f16073e35f0c
+	google.golang.org/protobuf v1.26.0
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0
 	gopkg.in/yaml.v2 v2.4.0
 )