OOIION-1575
Test to see if ui_theme exists before attempting to set it.  And provide defaults if necesary:
notifications_disabled: false
notifications_daily_digest: false
ui_theme_dark: false
A user should now be able to edit his/her email addr.
Merge pull request #321 from cgalvarino/fix_new_user_default_vars

OOIION-1575