serialcon: Remove some redundant VTE API calls

Latest VTE doesn't seem to provide set_emulation anymore, and the other
two seem to be the default anyways. This also avoids some VTE bindings
breakage on current rawhide:

https://bugzilla.redhat.com/show_bug.cgi?id=1114379

virtManager/serialcon.py

@@ -324,13 +324,9 @@ class vmmSerialConsole(vmmGObject):
 
     def init_terminal(self):
         self.terminal = Vte.Terminal()
-        self.terminal.set_cursor_blink_mode(Vte.TerminalCursorBlinkMode.ON)
-        self.terminal.set_emulation("xterm")
         self.terminal.set_scrollback_lines(1000)
         self.terminal.set_audible_bell(False)
         self.terminal.set_visible_bell(True)
-        self.terminal.set_backspace_binding(
-            Vte.TerminalEraseBinding.ASCII_BACKSPACE)
 
         self.terminal.connect("button-press-event", self.show_serial_rcpopup)
         self.terminal.connect("commit", self.console.send_data, self.terminal)