fix: test if mentor is set

src/buguser.py

@@ -91,6 +91,10 @@ def sponsor(user):
    
     u = mapped_login[user] 
 
+    if len(u["mentor"]) == 0:
+      print(f"The mentor is not set for {u}")
+      return
+
     print(u["mentor"])
     print(mapped_login[u["mentor"]]["name"])