Gazkits EDS Up, a couple of question for you:
- have you tried connecting to your device via adb while it is bootlooping? it's unlikely that it will respond, but you didn't say that you tried this; if it does respond, then you should be able to fix your build.prop file that way.
- does your device have an unlocked bootloader? if so, you can simply fastboot boot (or flash) your custom recovery, connect to your device via adb, remount /system in read-write mode, fix the build.prop file (i.e., undo your change), and reboot
Otherwise, you will need to find a stock factory image and way to flash it to your device (i.e., adb's only good when you have USB debugging enabled and adb components on both sides of the conversation), so you'd need fastboot (which requires an unlocked bootloader or whatever Alcatel uses for re-flashing stock ROMs.
Best of luck.