same build twice but get a big delta nupkg

[wszgrcy]

Squirrel version(s)
Which version(s) of the project are you using?
@electron-forge=>electron-wininstaller(5.0.0) built in
Description
I build 1.0.0 and update to server ,then change version build 1.0.1(only change version),generate delta nupkg,but size is too big

Steps to recreate

1. build
2. update to server
3. change version
4. build

Expected behavior
twice build only change version, but have 80MB packge,Equivalent to half of the original

Actual behavior
should smaller

Additional information