Python 3.7 does not support continue in a finally block

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

squinnondation/squinnondation.py

@@ -544,12 +544,10 @@ class Squirrel(Hazelnut):
             if key == "KEY_MOUSE":
                 try:
                     _, x, y, _, attr = curses.getmouse()
+                    self.handle_mouse_click(y, x, attr)
+                    continue
                 except curses.error:
                     # This is not a valid click
-                    pass
-                else:
-                    self.handle_mouse_click(y, x, attr)
-                finally:
                     continue
 
             self.handle_key_pressed(key)