PNI: og image url is broken on prod and staging

[mmmavis]

og:image url is invalid on prod and staging.

Template code

<meta property="og:image" content="{{request.scheme}}://{{request.get_host}}{% static "_images/buyers-guide/evergreen-social.jpg" %}">

Source code from PNI prod

<meta property="og:image" content="https://foundation.mozilla.orghttps://assets.mofoprod.net/static/_images/buyers-guide/evergreen-social.78437e17fd46.jpg">

Source code from PNI staging

<meta property="og:image" content="https://foundation.mofostaging.nethttps://assets.mofostaging.net/static/_images/buyers-guide/evergreen-social.78437e17fd46.jpg">

https://foundation.mozilla.orghttps://assets.mofoprod.net/static/_images/buyers-guide/evergreen-social.78437e17fd46.jpg is not a valid URL.

[mmmavis]

Changing it to content="{% static "_images/buyers-guide/evergreen-social.jpg"}" would solve the bug on prod and staging, but would break og:image locally as it generates a relative URL locally (e.g., /static/_images/buyers-guide/evergreen-social.jpg) and that we need an absolute URL for og:image to work.

og tags aren't useful for local development though. So I wonder if we can just ignore the local dev case?

[mmmavis]

Fix is in. (We are just gonna ignore local dev scenario.)