master ee3a4e3: Fix a dbus.el byte compilation warning

[Lars Ingebrigtsen]

branch: master
commit ee3a4e3d1be656cd0df71ed197dc5f102556f0e0
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Fix a dbus.el byte compilation warning
    
    * lisp/net/dbus.el (dbus-register-monitor): Silence a
    byte-compilation warning on systems without dbus.
---
 lisp/net/dbus.el | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lisp/net/dbus.el b/lisp/net/dbus.el
index 1e7f836..4116d29 100644
--- a/lisp/net/dbus.el
+++ b/lisp/net/dbus.el
@@ -2029,8 +2029,9 @@ either a method name, a signal name, or an error name."
            ",")
           rule (or rule ""))
 
-    (unless (ignore-errors (dbus-get-unique-name bus-private))
-      (dbus-init-bus bus 'private))
+    (when (fboundp 'dbus-get-unique-name)
+      (unless (ignore-errors (dbus-get-unique-name bus-private))
+        (dbus-init-bus bus 'private)))
     (dbus-call-method
      bus-private dbus-service-dbus dbus-path-dbus dbus-interface-monitoring
      "BecomeMonitor" `(:array :string ,rule) :uint32 0)