fix: umd template
fix: umd template

My fix is taken from the UMD templates project: https://github.com/umdjs/umd/blob/47e725735b854dfd93c1ca6fcebf1e018bd52606/templates/returnExportsGlobal.js#L32

Co-authored-by: Moandji Ezana <d0aad8b1eee13575776c6af5fd8574061dfd88b2@c-clearpartners.com>
toorshia/justgage