Fix `%s` used in format string warning
Fix `%s` used in format string warning

- Wrap everything in an NSString object.

chrisbtreats/SPTPersistentCache,chrisbtreats/SPTPersistentCache,FootballAddicts/SPTPersistentCache,chrisbtreats/SPTPersistentCache,chrisbtreats/SPTPersistentCache,spotify/SPTPersistentCache,FootballAddicts/SPTPersistentCache,spotify/SPTPersistentCache,iOSCowboy/SPTPersistentCache,iOSCowboy/SPTPersistentCache,FootballAddicts/SPTPersistentCache,iOSCowboy/SPTPersistentCache,FootballAddicts/SPTPersistentCache,spotify/SPTPersistentCache