Here is the original build.prop , just remove the txt extension.
I resolved with this method:
Download the file in this 3d on the pc and unpack:
http://xdaforums.com/oneplus-one/development/toolkit-oneplus-one-easy-toolkit-unlock-t2804322
Download supersu on phone SDcard:
http://download.chainfire.eu/451/SuperSU/UPDATE-SuperSU-v2.01.zip?retrieve_file=1
Restore system.img and recovery.img
Code:
fastboot flash system system.img
fastboot flash recovery recovery.img
Reboot the phone, go to Developer setting and uncheck "Update recovery CM", make the OTA, reboot.
Now flash your preferred recovery:
TWPR
Code:
fastboot flash recovery TWRP-2.7.1.0.img
PHILZ
Code:
fastboot flash recovery Philz.img
Reboot into recovery and flash supersu.
This procedure is 100% tested, you will not lose any data, just have to reinstall custom system app.
I don't know if restoring just the original build.prop works.