This If memory serves is for the webrep add-on, so it is going to be fairly active whilst you are browsing. So it isn't scanning that page for hours, it is seeking webrep information (urlinfo) from that link.
I have set the following exclusion in the web shield so that it doesn't scan that as I trust that location, if you accept the risk of making an exclusion this is what can be entered:
Copy and paste (Add) the content of the above into the web shield exclusions, see image example.
Edit non-critical typo