meson: fix static/shared split again

shared_library does not generate a sane pkg-config file because it
assumes we don't want dependencies.

Additionally, since we key off of buildstatic, when *not* using
buildstatic but attempting to build libalpm on its own as static using
-Ddefault_library=static, we are building and linking to a shared
libalpm anyway.

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

meson.build

@@ -363,8 +363,8 @@ libalpm_a = static_library(
   link_with : [libcommon],
   install : true)
 
-if not get_option('buildstatic')
-  libalpm = shared_library(
+if get_option('default_library') != 'static'
+  libalpm = library(
     'alpm',
     version : libalpm_version,
     link_whole: [libalpm_a],