[pitivi] Fix pylint assignment-from-no-return

[Thibault Saunier <tsaunier src gnome org>]

commit 63b2497afb9449a42709ec7c79da40707980712a
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Tue Oct 29 21:32:38 2019 +0100

    Fix pylint assignment-from-no-return

 pitivi/viewer/move_scale_overlay.py | 4 ++--
 pre-commit.hook                     | 1 -
 2 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/pitivi/viewer/move_scale_overlay.py b/pitivi/viewer/move_scale_overlay.py
index 61e39d51..ba9a19e8 100644
--- a/pitivi/viewer/move_scale_overlay.py
+++ b/pitivi/viewer/move_scale_overlay.py
@@ -64,7 +64,7 @@ class Handle:
         self.neighbours = []
 
     def _get_minimal_box_size(self):
-        pass
+        raise NotImplementedError
 
     def _needs_size_restriction(self, handle_position_compare, cursor_position_compare):
         pass
@@ -73,7 +73,7 @@ class Handle:
         pass
 
     def _restrict(self, handle_to_cursor):
-        pass
+        raise NotImplementedError
 
     def __update_window_position(self):
         self.__window_position = (self.position + self.__translation) * self._overlay.stack.window_size
diff --git a/pre-commit.hook b/pre-commit.hook
index 9cc7e0db..4d178720 100755
--- a/pre-commit.hook
+++ b/pre-commit.hook
@@ -30,7 +30,6 @@ pitivi/utils/proxy.py
 pitivi/utils/ui.py
 pitivi/utils/validate.py
 pitivi/utils/widgets.py
-pitivi/viewer/move_scale_overlay.py
 pitivi/viewer/viewer.py
 tests/common.py
 tests/test_medialibrary.py