x11/dunst fix mouseclicks not being processed

If BTN_LEFT=0 then left-clicks are dismissed as errors.

Also, apologies if this message is a repeat; it looks like
the first one never arrived.

Index: x11/dunst/patches/patch-src_settings_h
===================================================================
RCS file: /cvs/ports/x11/dunst/patches/patch-src_settings_h,v
retrieving revision 1.3
diff -u -p -r1.3 patch-src_settings_h
--- x11/dunst/patches/patch-src_settings_h 6 Jul 2022 19:30:02 -0000 1.3
+++ x11/dunst/patches/patch-src_settings_h 31 Oct 2023 03:08:27 -0000
@@ -5,7 +5,7 @@ Index: src/settings.h

#define LIST_END (-1)

-+enum mouse_button { BTN_LEFT, BTN_RIGHT, BTN_MIDDLE, BTN_TOUCH };
++enum mouse_button { BTN_LEFT=1, BTN_RIGHT, BTN_MIDDLE, BTN_TOUCH };
+
enum alignment { ALIGN_LEFT, ALIGN_CENTER, ALIGN_RIGHT };
enum vertical_alignment { VERTICAL_TOP, VERTICAL_CENTER, VERTICAL_BOTTOM };