Root cinder volume will not be rebuilt from new image during instance's rebuild

Issue

• I created an instance from image with root cinder volume. Root volume will not be rebuilt during instance's is rebuild using the same image.
• I created an instance from image with root cinder volume. Root volume will not be rebuilt during instance's is rebuild when I provide another source image.
• Cinder root volume remains unchanged during instance's rebuild (it isn't re-created using configured source glance image).
• Cinder root volume remains unchanged during instance's rebuild with custom glance image.
• OpenStack bug 1482040