Unchecking all search field boxes in Agreements carries out search with no fields

Overview:

If you enter text into the search box and uncheck all the field boxes (Name, Alternative name, Description) a search is carried out with no match parameter value

Steps to Reproduce:

1. Open the developer console network tab
2. Open Agreements search
3. Enter a term in the test search box and click search - observe search carried out correctly with match parameters `match=name&match=alternateNames.name&match=description`
4. Check "Name" option - observe search carried out with parameter `match=name`
5. Uncheck "Name" option - observe search carried out with no value set for `match=` 

Expected Results:

the search carried out when you uncheck the name option should be have the match parameters `match=name&match=alternateNames.name&match=description`