Fix botch in forward.c flags code.

Thanks to Matthias Anfree for spotting this.

src/forward.c

@@ -810,9 +810,9 @@ void reply_query(int fd, int family, time_t now)
 	    {
 	      header->hb3 &= ~(HB3_QR | HB3_AA | HB3_TC);
 	      header->hb4 &= ~(HB4_RA | HB4_RCODE | HB4_CD | HB4_AD);
-	      if (forward->flags |= FREC_CHECKING_DISABLED)
+	      if (forward->flags & FREC_CHECKING_DISABLED)
 		header->hb4 |= HB4_CD;
-	      if (forward->flags |= FREC_AD_QUESTION)
+	      if (forward->flags & FREC_AD_QUESTION)
 		header->hb4 |= HB4_AD;
 	      if (forward->flags & FREC_DO_QUESTION)
 		add_do_bit(header, nn,  (unsigned char *)pheader + plen);