Copy Fork values when re-started build

[bradrydzewski]

There is a bug in the code that re-starts a build where the Fork value is not copied to the new build object. As a result, the build is rejected when Forks are disabled.

		hook := &core.Hook{
			Trigger:      user.Login,
			Event:        prev.Event,
			Action:       prev.Action,
			Link:         prev.Link,
			Timestamp:    prev.Timestamp,
			Title:        prev.Title,
			Message:      prev.Message,
			Before:       prev.Before,
			After:        prev.After,
			Ref:          prev.Ref,
+			Fork:         prev.Fork,
			Source:       prev.Source,
			Target:       prev.Target,
			Author:       prev.Author,
			AuthorName:   prev.AuthorName,
			AuthorEmail:  prev.AuthorEmail,
			AuthorAvatar: prev.AuthorAvatar,
			Sender:       prev.Sender,
			Params:       map[string]string{},
		}

[1] https://github.com/drone/drone/blob/master/handler/api/repos/builds/retry.go#L66

[bradrydzewski]

fixed in master