[FIX] web: correctly handle admin svg images in channel
[FIX] web: correctly handle admin svg images in channel

When posting an svg image, Odoo tries to resize it for thumbnailing
(like any image).
However this is of no interest since this is a vectorial file format, and
furthermore it distastefully makes the image library Pillow crash, since it only
supports raster formats.
The result would be a broken thumbnail instead of the image itself.

By not setting the thumbnail size if the mimetype contains svg,
we ignore the thumbnailing altogether.

Note that this only applies to the admin user, as otherwise the file is
treated as binary and thus no thumbnailing occurs anyway.

opw 1841153

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo