Wrong meta info at issueComments on github migration

[6543]

@lunny if I migrate a repo with issues:

comments are generated wich have the correct creation timestamp but update-timestamp is "1970-01-01T01:00:00+01:00"

[bagasme]

@6543 Beginning Unix time epoch?

[6543]

exactly -> migration simply dont set time on updated attribute

[6543]

updated should never be less than created 😅 ...