Remove repeated BackupNAT instance definition.

cloudformation_templates/edx-reference-architecture.json

@@ -1444,50 +1444,6 @@
         }
       }
     },
-    "BackupNATIPAddress":{
-      "Type":"AWS::EC2::EIP",
-      "Properties":{
-        "Domain":"vpc",
-        "InstanceId":{
-          "Ref":"BackupNATDevice"
-        }
-      }
-    },
-    "BackupNATDevice":{
-      "Type":"AWS::EC2::Instance",
-      "Properties":{
-        "InstanceType":{
-          "Ref":"NATInstanceType"
-        },
-        "KeyName":{
-          "Ref":"KeyName"
-        },
-        "SubnetId":{
-          "Ref":"PublicSubnet02"
-        },
-        "SourceDestCheck":"false",
-        "ImageId":{
-          "Fn::FindInMap":[
-            "AWSRegionArch2AMI",
-            {
-              "Ref":"AWS::Region"
-            },
-            {
-              "Fn::FindInMap":[
-                "AWSInstanceType2Arch",
-                "t1.micro",
-                "Arch"
-              ]
-            }
-          ]
-        },
-        "SecurityGroupIds":[
-          {
-            "Ref":"NATSecurityGroup"
-          }
-        ]
-      }
-    },
     "NATIPAddress":{
       "Type":"AWS::EC2::EIP",
       "Properties":{