Fix /msg user message
`command_talk` wants a string it can pick apart.  Pass that in from
`msg_command_cb`.
Fixes:
@@ -3121,7 +3121,7 @@ def msg_command_cb(data, current_buffer, args):
if who == "*":
who = EVENTROUTER.weechat_controller.buffers[current_buffer].slack_name
else:
- command_talk(data, current_buffer, who)
+ command_talk(data, current_buffer, "talk " + who)
if len(aargs) > 2:
message = aargs[2]
