component/libzip: add missing rpath and make shareable

find . -type f -executable | xargs ldd | egrep '(^\S|not found)' | grep -B1 'not found'
reported that this component creates binaries that are missing missing
rpath because libzip cannot be found.

Also enable shared as it looks shareable.

component/libzip/buildout.cfg

@@ -9,9 +9,10 @@ parts = libzip
 
 [libzip]
 recipe = slapos.recipe.cmmi
+shared = true
 url = https://libzip.org/download/libzip-1.5.2.tar.xz
 md5sum = f9dd38d273bcdec5d3d1498fe6684f42
-location = ${buildout:parts-directory}/${:_buildout_section_name_}
+location = @@LOCATION@@
 configure-command =
   mkdir build && cd build && \
   ${cmake:location}/bin/cmake \
@@ -25,3 +26,4 @@ environment =
   PATH=${cmake:location}/bin:%(PATH)s
   CMAKE_INCLUDE_PATH=${zlib:location}/include:${bzip2:location}/include
   CMAKE_LIBRARY_PATH=${zlib:location}/lib:${bzip2:location}/lib
+  LDFLAGS=-L${:location}/lib -Wl,-rpath=${:location}/lib