MOBILE-530 Minor fix in fileExists
MOBILE-530 Minor fix in fileExists

dianjiaotong/dianjiaotong_apps_android,akinibrahim/moodlemobile,Nithis111/AIT-Tech,ingoscarmorenoc/ios7,vincent-nephila/amaumobile,Nithis111/AIT-Tech,moodlehq/moodlemobile,oustaban/moodlemobile,bakasa/moodle101,dianjiaotong/moodle_apps_android,navdeep300/moodlemobile,ingoscarmorenoc/ios5,Namikase/moodlemobile,ingoscarmorenoc/ios6,xrdcode/moodlemobile,4r1y4n/moodlemobile,moodlewebexapp/moodlemobile,ingoscarmorenoc/ios3,ardock/moodlemobile,bakasa/moodle101,jleyva/moodlemobile,marcusoft/moodlemobile,vmoll/moodlemobile,GG001/GG,techguru123/MoodM,ingeniuslearning/moodlemobile,sudeepnayak/moodlemobile,dianjiaotong/dianjiaotong_apps_android,CEDITE/FACETVirtual.Mobile-OLD,sergiopro14/moodlemobile,ubaldojmp/Moodle-CUC,taher552/tahfiz,elvincasem/moodlemobileous,Vedran91/moodlemobile,marcusoft/Aula-Virtual,tang7526/moodlemobile,marcusoft/moodlemobile,ingoscarmorenoc/ios6,techguru123/MoodM,sergiopro14/moodlemobile,clopezlga/moodlemobile,ingoscarmorenoc/ios5,Ilmawankh/modle-elearning,4r1y4n/moodlemobile,moodlewebexapp/moodlemobile,ubaldojmp/Moodle-CUC,stefobark/moodlemobile,iharris78/ctcswlapp,ingoscarmorenoc/ios4,sudeepnayak/moodlemobile,ingoscarmorenoc/ios4,ingoscarmorenoc/LLLLL,clopezlga/moodlemobile,CEDITE/FACETVirtual.Mobile-OLD,ingoscarmorenoc/ios3,xrdcode/moodlemobile,guozhenqiang/hit,taher552/tahfiz,GG001/GG,muhammadumarpatel/felarc,tang7526/moodlemobile,ingoscarmorenoc/ios7,akinibrahim/moodlemobile,Namikase/moodlemobile,vmoll/moodlemobile,Vedran91/moodlemobile,ardock/moodlemobile,ingeniuslearning/moodlemobile,dianjiaotong/moodle_apps_android,Ilmawankh/modle-elearning,ingoscarmorenoc/ios2,marcusoft/Aula-Virtual,elvincasem/moodlemobileous,iharris78/ctcswlapp,ingoscarmorenoc/ios2,muhammadumarpatel/felarc,navdeep300/moodlemobile,oustaban/moodlemobile,danielsonnora/universidaderaffinato,moodlehq/moodlemobile,guozhenqiang/hit,vincent-nephila/amaumobile,stefobark/moodlemobile,yusa55/moodlemobile,danielsonnora/universidaderaffinato,knowngate/eduline