build-sys: meson: Correctly set up RPATH

This was being done automatically by autotools, now we need to manually
specify this for each executable/library with a dependency in a
non-standard directory.

src/modules/bluetooth/meson.build

@@ -28,5 +28,6 @@ libbluez5_util = shared_library('bluez5-util',
   include_directories : [configinc, topinc],
   dependencies : [libpulse_dep, libpulsecommon_dep, libpulsecore_dep, dbus_dep, sbc_dep],
   install : true,
+  install_rpath : privlibdir,
   install_dir : modlibexecdir,
 )