[Windows] use double quotes for portable roslaunch-check command.

[seanyen]

On Windows, the single quotes will be passed the executable and won't be escaped. In this case, it causes that this line always returns None and throws exceptions like below.

ros_comm/tools/roslaunch/scripts/roslaunch-check

Line 88 in 902fb00

pkg = rospkg.get_package_name(roslaunch_path)

Traceback (most recent call last):
  File "C:\opt\ros\melodic\x64\share\roslaunch\scripts\roslaunch-check", line 90, in <module>
    pkg_dir = r.get_path(pkg)
  File "C:\opt\python27amd64\lib\site-packages\rospkg\rospack.py", line 203, in get_path
    raise ResourceNotFound(name, ros_paths=self._ros_paths)
rospkg.common.ResourceNotFound: <exception str() failed>

[seanyen]

@dirk-thomas This is ready for review and merge. Thanks!

[dirk-thomas]

@ros-pull-request-builder retest this please

[dirk-thomas]

Thanks for the patch.