[gvfs] build: Fix gdu monitor build when gudev is disabled

[Ting-Wei Lan <lantw src gnome org>]

commit 75b509703d5f1f4b3904c2b1a84a771eb049d3b5
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Wed Jan 24 18:49:03 2018 +0800

    build: Fix gdu monitor build when gudev is disabled
    
    https://bugzilla.gnome.org/show_bug.cgi?id=786149

 monitor/gdu/meson.build |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/monitor/gdu/meson.build b/monitor/gdu/meson.build
index 3117b1d..7713998 100644
--- a/monitor/gdu/meson.build
+++ b/monitor/gdu/meson.build
@@ -46,12 +46,15 @@ sources = files(
 
 deps = glib_deps + [
   gdu_dep,
-  gudev_dep,
   libgvfscommon_dep,
   libgvfscommon_monitor_dep,
   libgvfsproxyvolumemonitordaemon_noin_dep
 ]
 
+if enable_gudev
+  deps += gudev_dep
+endif
+
 cflags = [
   '-DG_LOG_DOMAIN="GVFS-Gdu"',
   '-DGDU_API_IS_SUBJECT_TO_CHANGE',