systemvm: Update ISO URLs to the latest (#2747)

Update ISO URLs to the latest as the old URLs are broken. Base template updated for Debian 9.5.0.

Author: khos2ow

tools/appliance/builtin/template.json

@@ -23,8 +23,8 @@
       "disk_interface": "virtio",
       "net_device": "virtio-net",
 
-      "iso_url": "http://mirror.nbrc.ac.in/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1708.iso",
-      "iso_checksum": "5848f2fd31c7acf3811ad88eaca6f4aa",
+      "iso_url": "http://mirror.nbrc.ac.in/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1808.iso",
+      "iso_checksum": "13675c6f74880e7ff3481b91bdaf925ce81bda8f",
       "iso_checksum_type": "md5",
 
       "vm_name": "builtin",

tools/appliance/systemvmtemplate/template.json

@@ -38,8 +38,8 @@
       "disk_interface": "virtio",
       "net_device": "virtio-net",
 
-      "iso_url": "https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-9.4.0-amd64-netinst.iso",
-      "iso_checksum": "345c4e674dc10476e8c4f1571fbcdba4ce9788aa5584c5e2590ab3e89e7bb9acb370536f41a3ac740eb92b6aebe3cb8eb9734874dd1658c68875981b8351bc38",
+      "iso_url": "https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-9.5.0-amd64-netinst.iso",
+      "iso_checksum": "efe75000c066506326c74a97257163b3050d656a5be8708a6826b0f810208d0a58f413c446de09919c580de8fac6d0a47774534725dd9fdd00c94859e370f373",
       "iso_checksum_type": "sha512",
 
       "vm_name": "systemvmtemplate",