Trigger load of user data in User::getBlockStatus() before we

Trigger load of user data in User::getBlockStatus() before we
start changing member variables.

Otherwise something ends up stomping on $this->mBlockedby when
things get lazy-loaded later, causing false positive block hits
due to -1 !== 0. Probably session-related... Nothing should be
overwriting mBlockedby, surely?

This was giving me blank "you are blocked" messages.... but only
when doing *section edits on SSL*, not regular edits, nor section
edits on non-SSL wikipedia. Weeeeeeird