ubuntu-18.04.3-server-amd64.iso longer hosted at http://cdimage.ubuntu.com/ubuntu

[basictheprogram]

http://cdimage.ubuntu.com/ubuntu/releases/18.04/release/ubuntu-18.04.3-server-amd64.iso is no longer hosted only ubuntu-18.04.4-server-amd64.iso is hosted

http://cdimage.ubuntu.com/ubuntu/releases/18.04/release/ubuntu-18.04.3-server-amd64.iso

e2ecdace33c939527cbc9e8d23576381c493b071107207d2040af72595f8990b *ubuntu-18.04.4-server-amd64.iso

diff --git a/ubuntu1804.json b/ubuntu1804.json
index 0531b8f..d9ce235 100644
--- a/ubuntu1804.json
+++ b/ubuntu1804.json
@@ -3,10 +3,10 @@
   "vm_name": "ubuntu1804",
   "cpus": "1",
   "disk_size": "65536",
-  "iso_checksum": "7d8e0055d663bffa27c1718685085626cb59346e7626ba3d3f476322271f573e",
+  "iso_checksum": "e2ecdace33c939527cbc9e8d23576381c493b071107207d2040af72595f8990b",
   "iso_checksum_type": "sha256",
   "iso_name": "ubuntu-18.04.3-server-amd64.iso",
-  "iso_url": "http://cdimage.ubuntu.com/ubuntu/releases/18.04/release/ubuntu-18.04.3-server-amd64.iso",
+  "iso_url": "http://cdimage.ubuntu.com/ubuntu/releases/18.04/release/ubuntu-18.04.4-server-amd64.iso",
   "memory": "512",
   "preseed": "preseed.cfg",
   "install_vagrant_key": "true"

I'll try to submit a PR tomorrow.