Version 1.9.2 breaks passing an object as a parameter to the expire method

[opensourceame]

Version 1.9.2 breaks passing an object as a parameter for the expire time

in 1.9.0 this works:

r = Redis.new
r.set(:a, 1)
r.expire(:a, 1.hour) # ActiveSupport::Duration object

in 1.9.2 it's broken:

r = Redis.new
r.set(:a, 1)
r.expire(:a, 1.hour) # ActiveSupport::Duration object

TypeError: Unsupported command argument type: ActiveSupport::Duration

IMO expire should cast to integer if the object responds to to_i.