Make fixed-architecture job scheduling possible
    
    Using `match_host_arch: True` in the trigger configuration for a task is
    now possible to force the task execution to the host with the same
    architecture as the item under test (remember, that the arch of the item
    under test is extracted from the FedMSG data).
    By default, the value is presumed to be False, meaning that the tests do
    not really care about the architecture of the host (e.g. do not install
    packages) for their execution.
    
    For example, if rpmgrill installed the package as as the part of the
    testing process, the config rule could look like this:
    
    - when: {message_type: KojiBuildPackageCompleted}
      do:
        - {tasks: [rpmgrill], match_host_arch: True}