update go-getter v1.7.3

Fixes regression in v1.7.2 where GIT_SSH_COMMAND would always be
overwritten.

go.mod

@@ -41,7 +41,7 @@ require (
 	github.com/hashicorp/go-azure-helpers v0.43.0
 	github.com/hashicorp/go-checkpoint v0.5.0
 	github.com/hashicorp/go-cleanhttp v0.5.2
-	github.com/hashicorp/go-getter v1.7.2
+	github.com/hashicorp/go-getter v1.7.3
 	github.com/hashicorp/go-hclog v1.5.0
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/hashicorp/go-plugin v1.4.3

go.sum

@@ -649,8 +649,8 @@ github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtng
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-cleanhttp v0.5.2 h1:035FKYIWjmULyFRBKPs8TBQoi0x6d9G4xc9neXJWAZQ=
 github.com/hashicorp/go-cleanhttp v0.5.2/go.mod h1:kO/YDlP8L1346E6Sodw+PrpBSV4/SoxCXGY6BqNFT48=
-github.com/hashicorp/go-getter v1.7.2 h1:uJDtyXwEfalmp1PqdxuhZqrNkUyClZAhVeZYTArbqkg=
-github.com/hashicorp/go-getter v1.7.2/go.mod h1:W7TalhMmbPmsSMdNjD0ZskARur/9GJ17cfHTRtXV744=
+github.com/hashicorp/go-getter v1.7.3 h1:bN2+Fw9XPFvOCjB0UOevFIMICZ7G2XSQHzfvLUyOM5E=
+github.com/hashicorp/go-getter v1.7.3/go.mod h1:W7TalhMmbPmsSMdNjD0ZskARur/9GJ17cfHTRtXV744=
 github.com/hashicorp/go-hclog v0.0.0-20180709165350-ff2cf002a8dd/go.mod h1:9bjs9uLqI8l75knNv3lV1kA55veR+WUPSiKIWcQHudI=
 github.com/hashicorp/go-hclog v0.8.0/go.mod h1:5CU+agLiy3J7N7QjHK5d05KxGsuXiQLrjA0H7acj2lQ=
 github.com/hashicorp/go-hclog v0.9.2/go.mod h1:5CU+agLiy3J7N7QjHK5d05KxGsuXiQLrjA0H7acj2lQ=