give focus to conversation textview when we insensitive message_textview so...

give focus to conversation textview when we insensitive message_textview so that it can receive Ctrl+1,2,3. Fixes #2263

src/chat_control.py

@@ -792,6 +792,7 @@ class ChatControlBase(MessageControl):
 	def got_disconnected(self):
 		self.msg_textview.set_sensitive(False)
 		self.msg_textview.set_editable(False)
+		self.conv_textview.tv.grab_focus()
 		self.xml.get_widget('send_button').set_sensitive(False)
 
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