go.mod: upgrade go-duktape to hide unused function warning (#21168)

Author: ucwong

go.mod

@@ -64,7 +64,7 @@ require (
 	golang.org/x/text v0.3.2
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
 	gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce
-	gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200316214253-d7b0ff38cac9
+	gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200603215123-a4a8cb9d2cbc
 	gopkg.in/urfave/cli.v1 v1.20.0
 	gotest.tools v2.2.0+incompatible // indirect
 )

go.sum

@@ -218,8 +218,8 @@ gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce h1:+JknDZhAj8YMt7GC73Ei8pv4MzjDUNPHgQWJdtMAaDU=
 gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce/go.mod h1:5AcXVHNjg+BDxry382+8OKon8SEWiKktQR07RKPsv1c=
-gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200316214253-d7b0ff38cac9 h1:ITeyKbRetrVzqR3U1eY+ywgp7IBspGd1U/bkwd1gWu4=
-gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200316214253-d7b0ff38cac9/go.mod h1:uAJfkITjFhyEEuUfm7bsmCZRbW5WRq8s9EY8HZ6hCns=
+gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200603215123-a4a8cb9d2cbc h1:17cdygvFw3DEyNMh81Bk687W74d5pcC5qEKQICv9N6g=
+gopkg.in/olebedev/go-duktape.v3 v3.0.0-20200603215123-a4a8cb9d2cbc/go.mod h1:uAJfkITjFhyEEuUfm7bsmCZRbW5WRq8s9EY8HZ6hCns=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/urfave/cli.v1 v1.20.0 h1:NdAVW6RYxDif9DhDHaAortIu956m2c0v+09AZBPTbE0=