nonlib/OSC: Don't try to send feedback to non-existent path.

Closes #227.

lib/ntk

@@ -1 +1 @@
-Subproject commit 92365eca0f9a6f054abc70489c009aba0fcde0ff
+Subproject commit 1e3f5106d404562902bed2983403301db24a3f78

nonlib/OSC/Endpoint.C

@@ -1085,7 +1085,7 @@ namespace OSC
               i != _translations.end();
               i++ )
         {
-            if ( ! strcmp( i->second.path.c_str(), path ) )
+            if ( path && ! strcmp( i->second.path.c_str(), path ) )
             {
                 /* found it */
                 if ( !i->second.suppress_feedback && i->second.current_value != v )