Update Azure template

- Remove Debian 9, which is EOL after June 30, 2022.

azure/README-zh.md

@@ -9,7 +9,7 @@
  - Username for VPN **and** SSH （用户名）
  - Password for VPN **and** SSH （密码）
  - IPsec Pre-Shared Key for VPN （IPsec 预共享密钥）
- - Operating System Image （操作系统镜像，Ubuntu 22.04/20.04/18.04 或 Debian 9）
+ - Operating System Image （操作系统镜像，Ubuntu 22.04, 20.04 或 18.04）
  - Virtual Machine Size （虚拟机大小，默认值： Standard_B1s）
 
 **注：** \*不要\* 在值中使用这些字符： `\ " '`

azure/README.md

@@ -9,7 +9,7 @@ Customizable with the following options:
  - Username for VPN **and** SSH
  - Password for VPN **and** SSH
  - IPsec Pre-Shared Key for VPN
- - Operating System Image (Ubuntu 22.04/20.04/18.04 or Debian 9)
+ - Operating System Image (Ubuntu 22.04, 20.04 or 18.04)
  - Virtual Machine Size (Default: Standard_B1s)
 
 **Note:** DO NOT use these special characters within values: `\ " '`

azure/azuredeploy.json

@@ -26,12 +26,11 @@
       "allowedValues": [
         "ubuntu22.04",
         "ubuntu20.04",
-        "ubuntu18.04",
-        "debian9"
+        "ubuntu18.04"
       ],
       "defaultValue": "ubuntu22.04",
       "metadata": {
-        "description": "OS to use. Ubuntu 22.04/20.04/18.04 or Debian 9."
+        "description": "OS to use. Ubuntu 22.04, 20.04 or 18.04."
       }
     },
     "VMSize": {
@@ -80,12 +79,6 @@
       "sku": "18.04-LTS",
       "version": "latest"
     },
-    "debian9": {
-      "publisher": "credativ",
-      "offer": "Debian",
-      "sku": "9",
-      "version": "latest"
-    },
     "installScriptURL": "https://raw.githubusercontent.com/hwdsl2/setup-ipsec-vpn/master/azure/install.sh",
     "installCommand": "[concat('sh install.sh ', variables('quote'), parameters('preSharedKey'), variables('quote'), ' ', variables('quote'), parameters('username'), variables('quote'), ' ', variables('quote'), parameters('password'), variables('quote'))]"
   },