fix: Fixes default values in speakerstats and conf duration modules.

resources/prosody-plugins/mod_conference_duration.lua

 local conference_duration_component
-    = module:get_option_string(
-        "conference_duration_component", "conferenceduration"..module.host);
+    = module:get_option_string("conference_duration_component", "conferenceduration."..module.host);
 
 module:add_identity("component", "conference_duration", conference_duration_component);

resources/prosody-plugins/mod_speakerstats.lua

 local speakerstats_component
-    = module:get_option_string(
-        "speakerstats_component", "speakerstats"..module.host);
+    = module:get_option_string("speakerstats_component", "speakerstats."..module.host);
 
 -- Advertise speaker stats so client can pick up the address and start sending
 -- dominant speaker events