Remove dubious link to MockObjects Web site in reference manual

[dspasic]

During the documentation Unit Testing 0 I came across the following
reference which is very confusing. It can be found in the Servlet API
section. There is a link (MockObjects), but it points to a dubious page:
https://mobilebarhawaii.com/. I tried to find the mentioned mock framework
to correct it afterwards. But could not find anything. If this is the case,
I suggest to adjust this part accordingly by removing the link.