[gitg] meson: Add libdir on gitg's rpath

[Alberto Fanjul <albfan src gnome org>]

commit c83122140a998b3026a56cb2688f5675d5180b18
Author: Iñigo Martínez <inigomartinez gmail com>
Date:   Mon Dec 24 10:30:58 2018 +0100

    meson: Add libdir on gitg's rpath
    
    If `libdir` is set in a custom directory, `gitg` will not be able to
    find `libgitg` and `libgitg-ext`.
    
    `libdir` has been set as the `rpath` in `gitg` so when a custom
    `libdir` directory is used `libgitg` and `libgitg-ext` will be
    found.
    
    Fixes #174

 gitg/meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gitg/meson.build b/gitg/meson.build
index 53b1fa72..930f8013 100644
--- a/gitg/meson.build
+++ b/gitg/meson.build
@@ -134,4 +134,5 @@ executable(
   c_args: cflags,
   vala_args: vala_flags,
   install: true,
+  install_rpath: gitg_libdir,
 )