config: ensure .gitconfig is loaded before Unmarshal call

config/config.go

@@ -131,6 +131,8 @@ func NewFrom(v Values) *Configuration {
 // Otherwise, the field will be set to the value of calling the
 // appropriately-typed method on the specified environment.
 func (c *Configuration) Unmarshal(v interface{}) error {
+	c.loadGitConfig()
+
 	into := reflect.ValueOf(v)
 	if into.Kind() != reflect.Ptr {
 		return fmt.Errorf("lfs/config: unable to parse non-pointer type of %T", v)