sync content with import remotes

sync content with import remotes

This didn't used to be needed because importKeys would import all
content and so doing another pass was redundant.

But since 40017089f268391f79226592850b58855cdbf808 it uses
importChanges, so only new files are imported. If a file that was
already imported before was dropped, that would prevent sync --content
from gettng its content again.

Sponsored-by: Jack Hill on Patreon