Build the tls config generator only with Go versions compatible with Go 1.12

ccojocar · gcmurphy · commit 43e366471357 · 2019-09-10T11:57:18.000+10:00
Signed-off-by: Cosmin Cojocar &lt;cosmin.cojocar@gmx.ch&gt;
diff --git a/cmd/tlsconfig/tlsconfig.go b/cmd/tlsconfig/tlsconfig.go
@@ -1,3 +1,5 @@
+// +build go1.12
+
 package main
 
 import (
