[gnome-system-monitor] remove an unused include

[Robert Roth <robertroth src gnome org>]

commit fe3f68552b1d9d2be7b4c9f8b89929639ce4c70b
Author: Elias Aebi <353-eyelash users noreply gitlab gnome org>
Date:   Sun Jan 16 11:35:52 2022 +0100

    remove an unused include

 src/lsof.cpp | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/src/lsof.cpp b/src/lsof.cpp
index bdba6408..58041e81 100644
--- a/src/lsof.cpp
+++ b/src/lsof.cpp
@@ -1,7 +1,6 @@
 /* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 #include <config.h>
 
-#include <gtkmm/messagedialog.h>
 #include <glib/gi18n.h>
 #include <glibtop/procopenfiles.h>