Fix an if statement as suggested at https://github.com/smartdevicelink/sdl_ios/pull/1613#discussion_r472186070. Also fixed a signed/unsigned warning.
Fix an if statement as suggested at https://github.com/smartdevicelink/sdl_ios/pull/1613#discussion_r472186070.
Also fixed a signed/unsigned warning.

smartdevicelink/sdl_ios,smartdevicelink/sdl_ios,smartdevicelink/sdl_ios,smartdevicelink/sdl_ios,smartdevicelink/sdl_ios