[meld/ui-next] Add back missed new-tab accelerator

[Kai Willadsen <kaiw src gnome org>]

commit 25427f39f5329af29629a5e58099508060c1268b
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Mar 1 10:16:40 2019 +1000

    Add back missed new-tab accelerator

 meld/accelerators.py | 1 +
 meld/meldwindow.py   | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/meld/accelerators.py b/meld/accelerators.py
index 2485e7f2..3b86a33a 100644
--- a/meld/accelerators.py
+++ b/meld/accelerators.py
@@ -26,6 +26,7 @@ def register_accels(app: Gtk.Application):
         ('view.vc-commit', '<Primary>M'),
         ('view.vc-console-visible', 'F9'),
         ('win.close', '<Primary>W'),
+        ('win.new-tab', '<Primary>N'),
         ("win.stop", "Escape"),
     )
     for (name, accel) in view_accels:
diff --git a/meld/meldwindow.py b/meld/meldwindow.py
index d0afd141..2f3df191 100644
--- a/meld/meldwindow.py
+++ b/meld/meldwindow.py
@@ -78,7 +78,7 @@ class MeldWindow(Gtk.ApplicationWindow):
         # Manually handle GAction additions
         actions = (
             ("close", self.action_close),
-            ("new-tab", self.on_action_new_tab_activate),
+            ("new-tab", self.action_new_tab),
             ("stop", self.action_stop),
         )
         for name, callback in actions:
@@ -238,7 +238,7 @@ class MeldWindow(Gtk.ApplicationWindow):
     def on_page_label_changed(self, notebook, label_text):
         self.set_title(label_text)
 
-    def on_action_new_tab_activate(self, action, parameter):
+    def action_new_tab(self, action, parameter):
         self.append_new_comparison()
 
     def action_close(self, *extra):