Gabby Agbonlahor has told Arsenal to accept they made a £100,000-a-week mistake and cut their losses on a player not up to the Gunners’ levels in the transfer window. This summer could be a period of upheaval in north London as Mikel Arteta looks to reshape his ranks. Arsenal have so far only welcomed Tommy Setford to the club as an Under-21 gem as a new recruit. David Raya also finalised a permanent transfer from Brentford this summer. Arteta is considering a huge revamp at Emirates Stadium after Arsenal finished second in the Premier League standings once again. They have ended the last two …