[FIX] theme_*: use correct header SCSS variable

This commit fixes the "Contact" header and the "default" header that
were not displaying correctly (in related themes) in the web editor
panel as expected.

task-2713578

closes odoo/design-themes#557

X-original-commit: f403f252bc
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

theme_notes/static/src/scss/primary_variables.scss

@@ -128,7 +128,7 @@ $o-website-values-palettes: (
         'navbar-font': 'Montserrat',
         'buttons-font': 'Montserrat',
         'link-underline': 'never',
-        'header-template': 'template_header_default',
+        'header-template': 'default',
         'footer-template': 'descriptive',
     ),
 );