libfcgi: Use SPDX license identifier
The fcgi license is covered by SPDX, the identifier however is not
obvious.
For details, see https://spdx.org/licenses/OML.html
[Peter: add spdx.org link]
Signed-off-by: Alexander Dahl <post@lespocky.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit b13d9ab380704ba4faf1e0295885797cb3341336)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>