Carla: Don't init Lv2World when not neded, fixes discovery duplicate errors

c++/carla-backend/lv2.cpp

@@ -457,6 +457,8 @@ public:
             lv2Options.oSampleRate.type    = CARLA_URI_MAP_ID_ATOM_DOUBLE;
             lv2Options.oSampleRate.value   = &lv2Options.sampleRate;
         }
+
+        Lv2World.init();
     }
 
     ~Lv2Plugin()

c++/carla-includes/carla_lv2.h

@@ -328,7 +328,6 @@ static inline
 const LV2_RDF_Descriptor* lv2_rdf_new(const LV2_URI URI)
 {
     Q_ASSERT(URI);
-    Lv2World.init();
 
     Lilv::Plugins lilvPlugins = Lv2World.get_all_plugins();