update HTTP.jl

[paraynaud]

update Project.toml and Manifest.toml accordingly to HTTP.jl

The purpose is to fix the error:

x = get_symbols("GOOG", "2018-12-13", "2019-06-28")
WARNING: both IOExtras and Base export "closewrite"; uses of it in module StreamRequest must be qualified
WARNING: both IOExtras and Base export "closewrite"; uses of it in module ConnectionPool must be qualified
ERROR: UndefVarError: closewrite not defined
...