vendor: bump urfave/cli to v1.22.6

This finally fixes the regression of not allowing -1 as an argument,
which is reported in https://github.com/urfave/cli/pull/1135.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

vendor/github.com/urfave/cli/flag_int_slice.go

@@ -22,7 +22,12 @@ func (f *IntSlice) Set(value string) error {
 
 // String returns a readable representation of this value (for usage defaults)
 func (f *IntSlice) String() string {
-	return fmt.Sprintf("%#v", *f)
+	slice := make([]string, len(*f))
+	for i, v := range *f {
+		slice[i] = strconv.Itoa(v)
+	}
+
+	return strings.Join(slice, ",")
 }
 
 // Value returns the slice of ints set by this flag
@@ -132,11 +137,62 @@ func (c *Context) GlobalIntSlice(name string) []int {
 func lookupIntSlice(name string, set *flag.FlagSet) []int {
 	f := set.Lookup(name)
 	if f != nil {
-		parsed, err := (f.Value.(*IntSlice)).Value(), error(nil)
-		if err != nil {
+		value, ok := f.Value.(*IntSlice)
+		if !ok {
 			return nil
 		}
-		return parsed
+		// extract the slice from asserted value
+		slice := value.Value()
+
+		// extract default value from the flag
+		var defaultVal []int
+		for _, v := range strings.Split(f.DefValue, ",") {
+			if v != "" {
+				intValue, err := strconv.Atoi(v)
+				if err != nil {
+					panic(err)
+				}
+				defaultVal = append(defaultVal, intValue)
+			}
+		}
+		// if the current value is not equal to the default value
+		// remove the default values from the flag
+		if !isIntSliceEqual(slice, defaultVal) {
+			for _, v := range defaultVal {
+				slice = removeFromIntSlice(slice, v)
+			}
+		}
+		return slice
 	}
 	return nil
 }
+
+func removeFromIntSlice(slice []int, val int) []int {
+	for i, v := range slice {
+		if v == val {
+			ret := append([]int{}, slice[:i]...)
+			ret = append(ret, slice[i+1:]...)
+			return ret
+		}
+	}
+	return slice
+}
+
+func isIntSliceEqual(newValue, defaultValue []int) bool {
+	// If one is nil, the other must also be nil.
+	if (newValue == nil) != (defaultValue == nil) {
+		return false
+	}
+
+	if len(newValue) != len(defaultValue) {
+		return false
+	}
+
+	for i, v := range newValue {
+		if v != defaultValue[i] {
+			return false
+		}
+	}
+
+	return true
+}