fix: vertexIdCnt should be in sync with vertex ids (boost)

source/armarx/navigation/server/GraphBuilder.h

@@ -70,7 +70,7 @@ namespace armarx::navigation::server
 
         core::Graph graph;
 
-        int64_t vertexIdCnt = 0;
+        int64_t vertexIdCnt = -1;
     };
 
 } // namespace armarx::navigation::server