Fix Nokia Contact Sorting Issue in RM-1137 and RM-1136 Models

A fix for importing contacts from older Nokia phones to models like RM-1137 and RM-1136 which the sorting in contacts list is based on last name. After the convertion is finished the out.vcf file must be renamed to backup.dat and placed in the backup folder of the phone's sd-card. Now the contacts can be restored via backup menu in settings.