graph: avoid add two edges with the same ID
graph: avoid add two edges with the same ID

skydive-project/skydive,lebauce/skydive,lebauce/skydive,lebauce/skydive,lebauce/skydive,skydive-project/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,skydive-project/skydive,lebauce/skydive,lebauce/skydive,lebauce/skydive,skydive-project/skydive,skydive-project/skydive