playground: Cleanup for veyron/release-issues#1157

Change-Id: Ia598d2ccd138ddc520343b6d40ea5d8ef62cdbdf
diff --git a/go/src/playground/builder/main.go b/go/src/playground/builder/main.go
index 10895bc..5047e51 100644
--- a/go/src/playground/builder/main.go
+++ b/go/src/playground/builder/main.go
@@ -36,7 +36,6 @@
 	"syscall"
 	"time"
 
-	vexec "v.io/x/ref/lib/exec/consts"
 	"v.io/x/ref/lib/flags/consts"
 
 	"playground/lib"
@@ -420,10 +419,6 @@
 	os.Unsetenv(consts.VeyronCredentials)
 	flag.Parse()
 
-	// TODO(cnicolaou): remove this when the isse below is resolved:
-	// https://github.com/veyron/release-issues/issues/1157
-	os.Setenv(vexec.ExecVersionVariable, "")
-
 	out = event.NewJsonSink(os.Stdout, !*verbose)
 
 	r, err := parseRequest(os.Stdin)