At Boyzone's long-awaited reunion concert in London's Emirates Stadium, there was recently a nasty surprise for around 44,000 spectators: band member Mikey Graham (53) was missing on stage at the beginning of the evening. While Ronan Keating (49), Shane Lynch (49) and Keith Duffy (51) opened the show, many fans waited in vain for their fourth Boyzone star. The event, which had been announced as the band's last farewell under the title "Two For T…