Only attempt to change user agent if it is provided as an argument
Only attempt to change user agent if it is provided as an argument

faceair/nativefier-slack,pixel9/nativefier,zucher/nativefier,gfpacheco/Nativefier,gfpacheco/Nativefier,jiahaog/Nativefier,jiahaog/Nativefier,zucher/nativefier,pixel9/nativefier,zucher/nativefier,gfpacheco/Nativefier,skewedlines/Nativefier,faceair/nativefier-slack,pixel9/nativefier,jiahaog/Nativefier,skewedlines/Nativefier,skewedlines/Nativefier