py3: use encoding.strtolocal() to convert str to bytes

Differential Revision: https://phab.mercurial-scm.org/D2459

hgext/patchbomb.py

@@ -85,6 +85,7 b' from mercurial.i18n import _'
 from mercurial import (
     cmdutil,
     commands,
+    encoding,
     error,
     formatter,
     hg,
@@ -669,7 +670,8 b' def email(ui, repo, *revs, **opts):'
         start_time = util.makedate()
 
     def genmsgid(id):
-        return '<%s.%d@%s>' % (id[:20], int(start_time[0]), socket.getfqdn())
+        return '<%s.%d@%s>' % (id[:20], int(start_time[0]),
+                               encoding.strtolocal(socket.getfqdn()))
 
     # deprecated config: patchbomb.from
     sender = (opts.get('from') or ui.config('email', 'from') or