compose: fix deep-copying of ImageBuild

I wanted to create a unit test for this method but then I decided not to.
The reason is that if we add another field to ImageBuild but fail to
modify the test it won't catch the bug. I think higher level testing is
needed to cover this function.

internal/compose/compose.go

@@ -47,6 +47,7 @@ func (ib *ImageBuild) DeepCopy() ImageBuild {
 	}
 	// Create new image build struct
 	return ImageBuild{
+		Id:          ib.Id,
 		Distro:      ib.Distro,
 		QueueStatus: ib.QueueStatus,
 		ImageType:   ib.ImageType,
@@ -55,6 +56,7 @@ func (ib *ImageBuild) DeepCopy() ImageBuild {
 		JobCreated:  ib.JobCreated,
 		JobStarted:  ib.JobStarted,
 		JobFinished: ib.JobFinished,
+		Size:        ib.Size,
 	}
 }