Don't split long and short description in "stg edit"

"stg edit" used to present the patch information like this:

  Short description

  From: ...
  Date: ...

  Long description

If the project follows the git convention with a single-line short
description and follwed by a blank line and the rest of the
description, this merely looks a little odd. However, for projects
that don't follow that convention, presenting the first line
separately is actively inconvenient; for example, it breaks emacs's
fill-paragraph command.

Signed-off-by: Karl Hasselström <kha@treskal.com>