If $line is empty, script generates an empty -o and alias doesn't work

I've used the 7.x-1.0-alpha4 version of this module successfully in the past. When I tried to use it on a current project, the alias failed with this error message:

command-line: line 0: Bad configuration option: default@vagrant

I had a look at vagrant.drush.inc and patched it so the alias now works! The problem was that the ssh-options key was getting an empty option flag at the end of the value.

I've patched vagrant.drush.inc and included it here. There doesn't seem to be a way to roll a patch against the 7.x-1.0-alpha version with git, so I rolled the patch against a "master" version and a "dev" version on my local system.

The 7.x-1.0 version of this module does only one thing; make vagrant aliases for host computers. The 7.x-2.0 version of this module seems to be going in another direction, and I've had no success using it on existing vagrants.