[Rd] typo in R online manual (PR#7200)

[trindade at stat.ufl.edu]

There is a mistake on the "Weibull Distribution" (base package) help 
page in the online docs (http://docs.stat.ufl.edu/R/doc/html/). The 
formula for Var(X) should have Gamma(1 + 1/a)^2 in place of Gamma(1 + 1/a).

-- 
Alex Trindade
Assistant Professor of Statistics
University of Florida
http://www.stat.ufl.edu/personnel/usrpages/trindade.shtml