incorporate fix for Go 1.16 from upstream PR go-openapi#138 on top of v0.19.8

As reported in go-openapi#137, changes in Go 1.16's `reflect` package cause the type validator to fail now. Incorporate a fix from go-openapi#138 to fix that.

For the time being, for internal compatibility and transitive dependency issues, we need to stick with v0.19.8. But to unblock upgrading to Go 1.16.0, we need this hotfix.

Author: anitgandhi

type.go

@@ -137,7 +137,7 @@ func (t *typeValidator) Applies(source interface{}, kind reflect.Kind) bool {
 func (t *typeValidator) Validate(data interface{}) *Result {
 	result := new(Result)
 	result.Inc()
-	if data == nil || reflect.DeepEqual(reflect.Zero(reflect.TypeOf(data)), reflect.ValueOf(data)) {
+	if data == nil {
 		// nil or zero value for the passed structure require Type: null
 		if len(t.Type) > 0 && !t.Type.Contains(nullType) && !t.Nullable { // TODO: if a property is not required it also passes this
 			return errorHelp.sErr(errors.InvalidType(t.Path, t.In, strings.Join(t.Type, ","), nullType))