make sure rpath is set in the resulting binary for libinotify.so

Index: meson.build
--- meson.build.orig
+++ meson.build
@@ -382,6 +382,7 @@ executable(
     sources + 'src/main.cpp',
     dependencies: dependencies,
     include_directories: 'src/external',
+    install_rpath: '${LOCALBASE}/lib/inotify',
     install: true,
 )
 
