Just pronounce it the way you pronounce it. I say gif, because in the uk we have a well known brand of lemon juice called jif so it makes sense to not pronounce gif un the same way. Maybe in other countries they dont have jif.
Well known? I wouldn't say that all I've never heard of it before you mentioned it and no one in my area has either and we all say gif with the soft g. It's a cute bottle for it though.
Really? Jif has been a thing since the 1950s. It was marketed to go on pancakes for shrove tuesday and thats always how ive known about it.
According to wikipedia it set a uk precident of protecting an unregistered trademark product when a US company made a similarly packaged lemon juice.