Is your feature request related to a problem? Please describe.
"jpeg" is a common file extension (in addition to "jpg") for JPEG images in GNU/Linux operating systems.
The problem is, when opening an existing image file: file filter "Image File" is active by default in the file selector window, but *.jpeg files are NOT listed (while they should). One has to disable the "Image File" filter in order to select this kind of files.

Describe the solution you'd like
Just include *.jpeg in the list of known Image Files :)

Additional context
N/A

Thank you.