Fix issue with pasting rich content from clipboard
Fix issue with pasting rich content from clipboard

When pasting rich content (e.g., copied from Google Docs) which
contains a mix of text and images, there are pieces with type =
"application/x-vnd.google-docs-image-clip+wrapped", which is not
supported, but get picked up by filter `indexOf('image')`.

Adding a slash to the pattern should help, since we are only
interested in types "image/png", "image/jpg" and "image/gif".

clbn/freefeed-gamma,clbn/freefeed-gamma,clbn/freefeed-gamma