pkg-config: only depends on libiconv

It has its own internal glib and doesn't use the system one

pkg-config/PKGBUILD

@@ -2,13 +2,13 @@
 
 pkgname=pkg-config
 pkgver=0.29.2
-pkgrel=2
+pkgrel=3
 pkgdesc="A system for managing library compile/link flags"
 arch=('i686' 'x86_64')
 url="https://www.freedesktop.org/wiki/Software/pkg-config/"
 license=('GPL')
 groups=('base-devel')
-depends=('glib2')
+depends=('libiconv')
 source=(https://pkgconfig.freedesktop.org/releases/${pkgname}-${pkgver}.tar.gz
         glib-cygwin.patch
         pkg-config-0.28-msys2.patch