tfinstall: Fix failing gitref test (#186)

diff --git a/tfinstall/gitref/git_ref_test.go b/tfinstall/gitref/git_ref_test.go
index 659eea1..b116da5 100644
--- a/tfinstall/gitref/git_ref_test.go
+++ b/tfinstall/gitref/git_ref_test.go
@@ -34,7 +34,7 @@
 		"branch v0.12": {"Terraform v0.12.", "refs/heads/v0.12"},
 		"tag v0.12.29": {"Terraform v0.12.29", "refs/tags/v0.12.29"},
 		// "commit 83630a7": {"Terraform v0.12.29", "83630a7003fb8b868a3bf940798326634c3c6acc"},
-		"empty": {"Terraform v0.15.", ""}, // should pull main, which is currently 0.15 dev
+		"empty": {"Terraform v1.", ""}, // should pull main, which is currently v1 dev
 	} {
 		c := c
 		t.Run(n, func(t *testing.T) {