private methods prevent them from being overriden on derived classes. In
GmailFolder we need to override copymessageto, so it can't be private.
Before this commit, copymessageto was made private in Base but not in
GmailFolder. The end result was that labels were not set when copying
the message content, and always needed to be set on the label copying
pass.
Pointyhat-to: Eygene Ryabinkin
Signed-off-by: Eygene Ryabinkin <rea@codelabs.ru>
1690e5f74e