Match time_of_day AI aspect against the current ToD id, not its name

This allows ToD-dependent AI configuration in pretty much all cases to
actually work. It seems all mainline WML was coded expecting this aspect
to match the ids, not names, which is only logical since the name
attribute is a user-visible translatable string -- using this for
matching would result in code that only works for certain translations
or lack thereof.

This bug appears to have been first introduced by Crab_ in commit
f788542095254e636c65ebae7055f2126df69ef5 ("fixed parsing of [target]
tags..."), for version 1.7.4.