build(deps): bump github.com/urfave/cli from 1.20.0 to 1.21.0 (#5928)

Bumps [github.com/urfave/cli](https://github.com/urfave/cli) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/urfave/cli/releases)
- [Changelog](https://github.com/urfave/cli/blob/master/CHANGELOG.md)
- [Commits](urfave/cli@v1.20.0...v1.21.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

go.mod

@@ -36,7 +36,7 @@ require (
 	github.com/syncthing/notify v0.0.0-20190709140112-69c7a957d3e2
 	github.com/syndtr/goleveldb v1.0.1-0.20190318030020-c3a204f8e965
 	github.com/thejerf/suture v3.0.2+incompatible
-	github.com/urfave/cli v1.20.0
+	github.com/urfave/cli v1.21.0
 	github.com/vitrun/qart v0.0.0-20160531060029-bf64b92db6b0
 	golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8
 	golang.org/x/net v0.0.0-20190613194153-d28f0bde5980

go.sum

@@ -4,6 +4,7 @@ github.com/AudriusButkevicius/pfilter v0.0.0-20190627213056-c55ef6137fc6 h1:Apvc
 github.com/AudriusButkevicius/pfilter v0.0.0-20190627213056-c55ef6137fc6/go.mod h1:1N0EEx/irz4B1qV17wW82TFbjQrE7oX316Cki6eDY0Q=
 github.com/AudriusButkevicius/recli v0.0.5 h1:xUa55PvWTHBm17T6RvjElRO3y5tALpdceH86vhzQ5wg=
 github.com/AudriusButkevicius/recli v0.0.5/go.mod h1:Q2E26yc6RvWWEz/TJ/goUp6yXvipYdJI096hpoaqsNs=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@@ -152,6 +153,8 @@ github.com/thejerf/suture v3.0.2+incompatible h1:GtMydYcnK4zBJ0KL6Lx9vLzl6Oozb65
 github.com/thejerf/suture v3.0.2+incompatible/go.mod h1:ibKwrVj+Uzf3XZdAiNWUouPaAbSoemxOHLmJmwheEMc=
 github.com/urfave/cli v1.20.0 h1:fDqGv3UG/4jbVl/QkFwEdddtEDjh/5Ov6X+0B/3bPaw=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
+github.com/urfave/cli v1.21.0 h1:wYSSj06510qPIzGSua9ZqsncMmWE3Zr55KBERygyrxE=
+github.com/urfave/cli v1.21.0/go.mod h1:lxDj6qX9Q6lWQxIrbrT0nwecwUtRnhVZAJjJZrVUZZQ=
 github.com/vitrun/qart v0.0.0-20160531060029-bf64b92db6b0 h1:okhMind4q9H1OxF44gNegWkiP4H/gsTFLalHFa4OOUI=
 github.com/vitrun/qart v0.0.0-20160531060029-bf64b92db6b0/go.mod h1:TTbGUfE+cXXceWtbTHq6lqcTvYPBKLNejBEbnUsQJtU=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=