v6.15.2

Bug Fixes

• docs: add warnings regarding no_prefix strategy (#891) (bbcbad9)
• seo: don't include queries in canonical link (d09ad9e), closes #912
• seo: enable canonical tag for all strategies (4ae4199)
• seo: enable self-referential canonical tags (b62fd39)
• add x-default hreflang tag for improved SEO (#922) (b35bc57)