build: allow installing examples to be disabled

In Nixpkgs, sysconfdir is not writeable in the sandbox in which
packages are built, so it's important for us to be able to disable
installing example files.  (We create configuration files and install
them into /etc separately through our "module system".)

Signed-off-by: Alyssa Ross <hi@alyssa.is>

meson.build

@@ -390,8 +390,10 @@ version_conf = {
 
 subdir('po')
 subdir('data')
-subdir('data/dispatcher-connection')
-subdir('data/dispatcher-fcc-unlock')
+if get_option('examples')
+  subdir('data/dispatcher-connection')
+  subdir('data/dispatcher-fcc-unlock')
+endif
 subdir('introspection')
 subdir('include')