How to restore cherry mobile quartz messing up the build prop
Reboot your phone to recovery.
Use adb to pull (read as copy) the build.prop from ROM/device

adb pull /system/build.prop c:\

Edit it back the way that it was.
Once edited save as normal
Use adb to push (read as paste) the build.prop to ROM/device

adb shell chmod 0644 /system/build.prop
adb remount

.....then

adb push c:\build.prop /system/

Reboot

adb reboot

Or

adb shell reboot