[Vala] [Genie] removing the empty line at end of file requirement

[Arc Riley <arcriley gmail com>]

At present, valac seems to be raising errors when the last line of a file is
indented (and is not followed by an empty line, etc), ie:

src/windows/_Thread.gs:75.16-75.15: error: syntax error, expected line end
or semicolon but got `dedent'

It's a small annoyance, but can we get this fixed in the next release?  It
would seem fairly trivial, just treating EOF as a full dedent