cmd: replace deprecate func use (caddyserver#5170)

Author: mohammed90

cmd/commands.go

@@ -456,7 +456,7 @@ argument of --directory. If the directory does not exist, it will be created.
 	`, rootCmd.Root().Name()),
 		DisableFlagsInUseLine: true,
 		ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
-		Args:                  cobra.ExactValidArgs(1),
+		Args:                  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			switch args[0] {
 			case "bash":