znc: allow running without modules

Now that we don't ship any modules by default, znc might be started
without any modules. Unfortunately znc refuses to start without any
modules, so patch out the appropriate check.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

net/znc/patches/110-add-playback-module.patch

@@ -1,7 +1,5 @@
-Index: znc-1.6.3/modules/playback.cpp
-===================================================================
 --- /dev/null
-+++ znc-1.6.3/modules/playback.cpp
++++ b/modules/playback.cpp
 @@ -0,0 +1,288 @@
 +/*
 + * Copyright (C) 2015 J-P Nurmi