[Lightning] Trouble to install of the info page of lightning

[Jochen Schmitt]

Hello,

a user has filed a bug, that they could not get the info page of lightning.

During the attemp to fix this issue in the package, I recorgnised the 
following message froth the install-info program:

install-info: warning: no info dir entry in `/usr/share/info//lightning.info.gz'

It may be nice, if you are able to fix this issue.

Best Regards:

Jochen Schmitt