meson: Remove unused header list

https://bugzilla.gnome.org/show_bug.cgi?id=793624
diff --git a/gst/debugutils/meson.build b/gst/debugutils/meson.build
index 648984d..1b9434d 100644
--- a/gst/debugutils/meson.build
+++ b/gst/debugutils/meson.build
@@ -9,14 +9,6 @@
   'gstwatchdog.c',
 ]
 
-debugutilsbad_headers = [
-  'gstchecksumsink.h',
-  'gstchopmydata.h',
-  'gstcompare.h',
-  'gstdebugspy.h',
-  'gstwatchdog.h',
-]
-
 gstdebugutilsbad = library('gstdebugutilsbad',
   debugutilsbad_sources,
   c_args : gst_plugins_bad_args,