Fix pvc label selector validation error

pkg/api/validation/schema.go

@@ -294,7 +294,7 @@ func (s *SwaggerSchema) isGenericArray(p swagger.ModelProperty) bool {
 }
 
 // This matches type name in the swagger spec, such as "v1.Binding".
-var versionRegexp = regexp.MustCompile(`^v.+\..*`)
+var versionRegexp = regexp.MustCompile(`^(v.+|unversioned)\..*`)
 
 func (s *SwaggerSchema) validateField(value interface{}, fieldName, fieldType string, fieldDetails *swagger.ModelProperty) []error {
 	allErrs := []error{}