prosody: plugin_paths cleared

we do not need community moules, therefore no path needs to be specified

templates/prosody/prosody.cfg.lua.j2

@@ -25,7 +25,7 @@ admins = { "alex@{{ prosody_domain_name }}", "tux@{{ prosody_domain_name }}" }
 -- Prosody will always look in its source directory for modules, but
 -- this option allows you to specify additional locations where Prosody
 -- will look for modules first. For community modules, see https://modules.prosody.im/
-plugin_paths = { "/usr/local/lib/prosody-modules" }
+plugin_paths = { }
 
 -- This is the list of modules Prosody will load on startup.
 -- It looks for mod_modulename.lua in the plugins folder, so make sure that exists too.