Fix number of expected pulsars in knope results tables
The lalapps_knope_collate_results.py script creates a table of known pulsar search results. It calculates the total number of sources being looked at by checking for directories in a given path - it assumes all these directories are for individual pulsars. So, if other "non-pulsar" directories exist in the given path it includes them in the total count. This patch makes the script check that a .ini file with the name of the pulsar (derived from the directory name) exists in the directories and only includes them in the count if it does.