[MacPorts] #60355: xonsh: Default variants typo

[MacPorts]

#60355: xonsh: Default variants typo
---------------------+-------------------------
  Reporter:  mf2k    |      Owner:  Schamschula
      Type:  defect  |     Status:  assigned
  Priority:  Normal  |  Milestone:
 Component:  ports   |    Version:  2.6.99
Resolution:          |   Keywords:
      Port:  xonsh   |
---------------------+-------------------------

Comment (by mf2k):

 I am happy to commit the fix.

-- 
Ticket URL: <https://trac.macports.org/ticket/60355#comment:1>
MacPorts <https://www.macports.org/>
Ports system for macOS