[strongSwan] Not using libsoup

[Tobias Brunner]

Hi Nicolas,

> Correct, the brew version of pkg-config was insufficient using `sudo port install pkgconfig` worked

The brew version works fine if you also use libraries installed via
brew, but you have to heed the console output that brew spits out when
it installs libraries (i.e. to use it correctly you have to define
several environment variables before or when calling configure, see e.g.
[1]).

Regards,
Tobias

[1]
https://git.strongswan.org/?p=strongswan.git;a=blob;f=scripts/test.sh;h=22e74033e276388545aeafbe7c941ea30fe72de9;hb=HEAD#l106