Added validation for essential headers. And disabled deleting it.

Backend/mocked-services/src/main/resources/static/js/datatransfer.js

@@ -269,7 +269,24 @@ function checkIfInputValid(input){
     return !(input == '' || input == null || input == undefined);
 }
 
+function checkIfHeaderEssential(key){
+
+    if( key == "Connection" || key == "Keep-Alive" || key == "Date" ){
+        return true; 
+    }
+    return false;
+
+}
+
 function buildRowHtml(key, value){
+
+    if(checkIfHeaderEssential(key)){
+        return '' + 
+        '<tr>' +
+            '<td><input class="key data-field" value="' + key + '" readonly></td>' +
+            '<td><input class="data-field" value="' + value + '"></td>' +
+        '</tr>';
+    } 
     return '' + 
     '<tr>' +
         '<td><input class="key data-field" value="' + key + '"></td>' +