Update test reference documentation link

Changes:
     - Find the updated link and update it.

Tested:
    - NA

Change-Id: Iac663b61c24b4c17e1400a5601598b906cd533c5
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/account_service/test_ipmi_redfish_user.robot b/redfish/account_service/test_ipmi_redfish_user.robot
index ff11564..fda4f8e 100644
--- a/redfish/account_service/test_ipmi_redfish_user.robot
+++ b/redfish/account_service/test_ipmi_redfish_user.robot
@@ -18,7 +18,7 @@
 ${admin_level_priv}     4
 ${operator_level_priv}  3
 ${readonly_level_priv}  2
-# Refer:  #openbmc/phosphor-user-manager/blob/master/user_mgr.cpp
+# Refer:  #openbmc/phosphor-user-manager/blob/master/user_mgr.hpp#L41
 # ipmiMaxUsers = 15;    <-- IPMI
 # maxSystemUsers = 30;  <-- Max system redfish account users allowed
 ${ipmi_max_num_users}   ${15}