Remove audio/gimmix

Starting the app shows a window, I leave user/password and host/port to
the defaults and click OK, then it dies:

(gdb) bt
#0 strlen () at /usr/src/lib/libc/arch/amd64/string/strlen.S:125
#1 0x00000a766b5c1914 in ?? ()
#2 0x00000a766b5cd6fb in ?? ()
#3 0x00000a78ff5263b9 in g_closure_invoke () from /usr/local/lib/libgobject-2.0.so.4200.12
#4 0x00000a78ff53efda in signal_emit_unlocked_R () from /usr/local/lib/libgobject-2.0.so.4200.12
#5 0x00000a78ff53fdda in g_signal_emit_valist () from /usr/local/lib/libgobject-2.0.so.4200.12
#6 0x00000a78ff5404a1 in g_signal_emit () from /usr/local/lib/libgobject-2.0.so.4200.12
#7 0x00000a78906de78c in gtk_real_button_released () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#8 0x00000a78ff5263b9 in g_closure_invoke () from /usr/local/lib/libgobject-2.0.so.4200.12
#9 0x00000a78ff53ed9a in signal_emit_unlocked_R () from /usr/local/lib/libgobject-2.0.so.4200.12
#10 0x00000a78ff53fdda in g_signal_emit_valist () from /usr/local/lib/libgobject-2.0.so.4200.12
#11 0x00000a78ff5404a1 in g_signal_emit () from /usr/local/lib/libgobject-2.0.so.4200.12
#12 0x00000a78906de31d in gtk_button_button_release () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#13 0x00000a78907ab1ae in _gtk_marshal_BOOLEAN__BOXED () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#14 0x00000a78ff5263b9 in g_closure_invoke () from /usr/local/lib/libgobject-2.0.so.4200.12
#15 0x00000a78ff53f117 in signal_emit_unlocked_R () from /usr/local/lib/libgobject-2.0.so.4200.12
#16 0x00000a78ff53fe23 in g_signal_emit_valist () from /usr/local/lib/libgobject-2.0.so.4200.12
#17 0x00000a78ff5404a1 in g_signal_emit () from /usr/local/lib/libgobject-2.0.so.4200.12
#18 0x00000a7890901696 in gtk_widget_event_internal () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#19 0x00000a78907a8d47 in gtk_propagate_event () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#20 0x00000a78907a8aca in gtk_main_do_event () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#21 0x00000a7872116f94 in gdk_event_dispatch () from /usr/local/lib/libgdk-x11-2.0.so.2400.0
#22 0x00000a796375c56f in g_main_context_dispatch () from /usr/local/lib/libglib-2.0.so.4201.5
#23 0x00000a796375c930 in g_main_context_iterate () from /usr/local/lib/libglib-2.0.so.4201.5
#24 0x00000a796375cd5a in g_main_loop_run () from /usr/local/lib/libglib-2.0.so.4201.5
#25 0x00000a78907a80e7 in gtk_main () from /usr/local/lib/libgtk-x11-2.0.so.2400.0
#26 0x00000a766b5d129b in ?? ()
#27 0x00000a766b5c13c1 in ?? ()
#28 0x0000000000000000 in ?? ()

Upstream is completely dead, even FreeBSD has marked their port as such
(EXPIRATION DATE: 2021-04-01, not sure what will happen then, though).

It does not work, depends on old Python and GTK and already carries a
local patch to cope with an cURL update.

OK?