fix(UOJContext.php): fix the bug that "page expires" occurs when accessing by localhost (#41)
fix(UOJContext.php): fix the bug that "page expires" occurs when accessing by localhost (#41)

To support subdomain cookies, an extra "." is added to the domain when setting the cookies.
However, this strategy fails on "localhost", because browsers do not recognize ".localhost".
So I add a check for this so that "localhost" is used as the cookie domain in this case.
UniversalOJ/UOJ-System,UniversalOJ/UOJ-System,UniversalOJ/UOJ-System,UniversalOJ/UOJ-System,UniversalOJ/UOJ-System,UniversalOJ/UOJ-System,UniversalOJ/UOJ-System