Make canonical always present, but set a default value if not defined

[PubliAlex]

Hello,

Lot of SEO software mark the absence of canonical URL as a bad point in term of SEO. It seems to be better to always define one, even if it's the same url than the page you are actually viewing.

Knowing that, I would change a little the SEO Storm component, removing the condition that check the canonical variable, but define a default value to the actual page when it's not present.

Best regards,

[PubliAlex]

Bump, what do you think about this PR ?

[dzapek]

Thanks @PubliAlex , this will be implemented in the next version of the plugin