NOTE: Not buildtested

- Update to version 3.26.3:
+ Extend workaround for bug 674885 (type initialisation deadlock
in GObject).
+ [CamelOfflineStore] Incorrect disconnect when going online.
+ [SMTP] Recognize rejected credentials during SASL
authentication.
+ [OAuth2] Enhance how expired or invalid access tokens are
handled.
+ [CalDAV/CardDAV] Always set error on failed connection attempt.
+ Correct typo in libgweather include directory variable.
+ Correct a failure condition in
cal_client_init_in_dbus_thread().
+ Bugs fixed: bgo#789147, bgo#790032, bgo#789549, bgo#790267,
bgo#790759, bgo#790887, bgo#790987.
+ Updated translations.