set static pass key for nrf51822 in example code--hrs with dfu ，nrf51822 reboot

[RiverYWang]

we add static pass key in example code hrs with dfu，but when connecting with phone，input passkey on phone，the nrf51822 will rebootdevice_manager_cnfg.h main.c

[Susheel Nuguru]

Hi RiverYWang, Thanks for understanding. I am feeling much better now. Did you manage to find the problem in the mean time? If not please let me know and I can look into the file.