Number of results comparison and number of results away from each other are incorrect

In legacy/trac#27338 (moved) we implemented restrictions on the minimum number of measurements there should be for a relay and how far away in time those results should be. There were a couple of implementation errors:

• the comparison for the minimun number of results uses ">", it should be ">="
• the list returned by the method that calculate how far away the results are, returns a list with one element, when it should be None (the first element was added for the comparison)