TWI: don't disable interrupt on address matching

Fixes #26

Author: facchinm

libraries/Wire/src/utility/twi.c

@@ -578,9 +578,6 @@ void TWI_SlaveAddressMatchHandler(){
 	slave_trans_status = TWIS_STATUS_BUSY;
 	slave_result = TWIS_RESULT_UNKNOWN;
 
-	/* Disable address & stop interrupt */
-	TWI0.SCTRLA &= ~(TWI_APIEN_bm | TWI_PIEN_bm);
-	
 	/* Send ACK, wait for data interrupt */
 	TWI0.SCTRLB = TWI_SCMD_RESPONSE_gc;