scanner saves wrong media count for by gps albums

the number of media in gps albums is higher than it should be, at least when protected content is present

See http://palmaro.qumran2.net/#!/_f (4127 media) and http://palmaro.qumran2.net/#!/_bg (6826 media).

Actually the wrong value in the json file is in the key numsMedia, but the scanner sets it with the value in numsProtectedMediaInSubTree[','], which is wrong too.

The issue is not present in myphotoshare installs with few media/albums (why?!?)