It's just reminding you that you haven't set _CONFIG2, which defaults to the following ...
Code:
@  __CONFIG _CONFIG2, _WRT_OFF & _BOR40V
But it you actually declare them, the warning will go away.

The M16F88X.INC is for the PM assembler.
But since you are using __CONFIG, you must be using MPASM.

In the C:\Program Files\Microchip\MPASM Suite folder,
the P16F887.inc file will have the correct config bit names.
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