Question: Which of the owner of Portstewart Football Club is a former Northern Ireland international footballer and manager?

Context paragraphs:
David Campbell (footballer): David Anthony Campbell (born 2 June 1965 in Eglington, Northern Ireland) is a former Northern Ireland international footballer who played in the midfield position.

Felix Healy: Felix Healy (born 27 September 1955 as Patrick Joseph Healy) is a former Northern Ireland international footballer who played for Coleraine and then became a football manager.  He has also worked as a media pundit and is currently part of the management team at First Division club Finn Harps, taking on the role of Director of football alongside manager Peter Hutton.

Kingsley Black: Kingsley Terence Black (born 22 June 1968) is a former Northern Ireland international footballer who played as a Midfielder from 1987 until 2002, notably in the Premier League for Nottingham Forest, as well as earning 30 caps for Northern Ireland, scoring once.

Harry Gregg: Henry "Harry" Gregg MBE (born 27 October 1932) is a former Northern Ireland international footballer and manager.  He made 25 appearances for Northern Ireland as a goalkeeper and played for Manchester United during the reign of Sir Matt Busby, with a total of 247 appearances for the club.  He is a survivor of the Munich air disaster in 1958.  Gregg also played for Doncaster Rovers and Stoke City and later went into management with Carlisle United, Crewe Alexandra, Shrewsbury Town and Swansea City.

Andy Smith (footballer, born 1980): Andrew William Smith (born 25 September 1980) is a former Northern Ireland international footballer.  He had a 16-year career playing professional and semi-professional football in Northern Ireland, England, Scotland, Belgium, and Portugal.  He also won 18 caps for Northern Ireland between 2003 and 2005 and one cap for the Northern Ireland B team in 2003.

Sammy Chapman: Samuel Edward Campbell Chapman (born 16 February 1938 in Belfast, Northern Ireland) is a former Northern Ireland international footballer and football manager.

Barry Hunter (footballer): Barry Hunter (born 18 November 1968, Coleraine, Northern Ireland) is a former Northern Ireland international footballer turned scout.

Jimmy Nicholl: James Michael Nicholl (born 28 February 1956) is a Canadian-born former Northern Ireland international footballer who played for several clubs, including Manchester United and Rangers.  He was mainly a right-back but could also play in other defensive roles.  Nicholl won a total of 73 international caps for Northern Ireland, scoring one goal.

Warren Feeney: Warren James Feeney (born 17 January 1981) is a former Northern Ireland international footballer and football manager.  In making his debut for the Northern Ireland national team, he became the third generation of his family to receive an international cap, after his father Warren Feeney, Sr. and grandfather Jim Feeney.

Portstewart F.C.: Portstewart Football Club is an intermediate, Northern Irish football club from Portstewart, County Londonderry.  The club was founded in 1968 and currently plays in the NIFL Premier Intermediate League.  The club's main colours are sky blue and navy.  Portstewart are nicknamed "The Seahawks".  The club's home ground, Mullaghacall, was officially opened in 1997 by Harry Gregg MBE.  Portstewart Reserves play in the Coleraine and District Morning League.

Supporting paragraphs: Portstewart F.C. Harry Gregg
Answer: Harry Gregg