Fix for Custom command plugin don't work

* https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=953153
* https://bugzilla.redhat.com/show_bug.cgi?id=1573927

terminatorlib/plugins/custom_commands.py

@@ -127,7 +127,7 @@ class CustomCommandsMenu(plugin.MenuItem):
       if command[-1] != '\n':
         command = command + '\n'
       for terminal in data['terminals']:
-        terminal.vte.feed_child(command,  len(command))
+        terminal.vte.feed_child_binary(command.encode(terminal.vte.get_encoding()))
 
     def configure(self, widget, data = None):
       ui = {}