If image file not provided, fall back to text in Dynamic Logo system
If image file not provided, fall back to text in Dynamic Logo system

teachers portal and fnde library both use same template, but
one calls for an image in its logo and the other does not.
To support this we should check if the image exists before including
it in the logo. Probably a good safety check to have anyway.

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib