[Factor-builds] mason on linux-x86-64: build loop error

[<fac...@gm...>]

Fatal error on ubuntu-mason

Unix system call failed:

Connection timed out (110)
(U) Quotation: [ set-namestack init-catchstack self quot>> call => stop ]
(O) Word: build-loop
(O) Word: update-sources
(O) Word: latest-boot-image
(O) Word: maybe-download-image
(O) Word: need-new-image?
(O) Word: download-checksum
(O) Word: download-checksums
(O) Word: http-request
(O) Word: http-request*
(O) Word: ( gensym )
(O) Word: <request-socket>
(O) Word: <client>
(O) Method: M\ array (client)
(O) Method: M\ object (client)
(O) Method: M\ object establish-connection
(O) Word: (throw-errno)
(O) Word: libc-error
(O) Method: M\ object throw
(U) Quotation: [
        OBJ-CURRENT-THREAD special-object error-thread set-global
        current-continuation => error-continuation set-global
        [ original-error set-global ] [ rethrow ] bi
    ]