[FIX] web_editor: properly convert image dimensions

Before this commit, the image dimensions were not properly converted
when converting HTML for e-mails.

opw-3144322

closes odoo/odoo#111793

X-original-commit: 1d5c8c9adf18aded19d945cd9b0f72eb9b8bbc72
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/static/src/js/backend/convert_inline.js

@@ -590,7 +590,7 @@ async function toInline($editable, cssRules, $iframe) {
                 value = attributeName === 'width' ? _getWidth(image) : _getHeight(image);;
             }
             image.setAttribute(attributeName, value);
-            image.style.setProperty(attributeName, image.getAttribute(attributeName));
+            image.style.setProperty(attributeName, value + 'px');
         };
     };