share_post: Reverting removal of summary for the plugin to be usable

[davidmarquis]

Otherwise code would not compile (summary variable is still used)

Closes #549

[kernc]

Nitpicking, but revert commits are best made with git revert (it's the message that matters).
You could further append a string like

Closes #549

to the commit message to also auto-close the associated open issue once the change is merged.

(You can change the message of this commit with git commit --amend and then git push --force.)

[davidmarquis]

Updated commit and pull request!

[justinmayer]

Thanks, @davidmarquis and @kernc, for your contributions here. (^_^)

[avaris]

Umm, won't this bring back the issues related to getpelican/pelican#1616? To be precise, accessing content.summary in content_object_init signal.

cc: @kernc @davidmarquis

[kernc]

Thanks! Indeed it should. 😃 It was even part of the same PR, just didn't contain the signal switch as I probably considered it, without any affected attributes, unnecessary.

Making the plugin fire on all_generators_finalized should fix it.

@davidmarquis, would you like to, since you messed it up? 😛