convert/gnuarch: wrap long line, format kwargs without spaces

hgext/convert/gnuarch.py

@@ -83,7 +83,8 b' class gnuarch_source(converter_source, c'
 
             archive = treeversion.split('/')[0]
             if archive not in self.archives:
-                self.ui.status(_('tree analysis stopped because it points to an unregistered archive %s...\n') % archive)
+                self.ui.status(_('tree analysis stopped because it points to '
+                                 'an unregistered archive %s...\n') % archive)
                 break
 
             # Get the complete list of revisions for that tree version