Update conditional to allow for empty filter

[snomos]

There are cases where it does not make sense to filter repos based on tags. We need to update

giellalt.github.io/assets/js/langtable.js

Lines 8073 to 8075 in 1f96fde

	if (doesTopicsHaveSomeFilter(repo.topics, filters)) {
	tbody.appendChild(addTR(repo));
	}

this to test for an empty or null filter, and in that case allow all repos to be added.

[snomos]

@albbas could you take a look?

[albbas]

Does 56b6e76 fix this problem?

[snomos]

Code looks good, will check more thoroughly tomorrow.