Catch SyntaxError exception and log nice error message

lib/server/grid-register.js

@@ -13,7 +13,7 @@ exports.registerNode = function (configFile) {
     if (data) {
       postRequest(data);
     } else {
-      logger.error("No data found in the node configuration  file to send to the grid");
+      logger.error("No data found in the node configuration file to send to the grid");
     }
   });
 };
@@ -31,7 +31,12 @@ function registerToGrid(options_post, jsonObject) {
 
 function postRequest(data) {
   //parse json to get hub host and port
-  var jsonObject = JSON.parse(data);
+  var jsonObject;
+  try {
+    jsonObject = JSON.parse(data);
+  } catch(e) {
+    return logger.error("Syntax error in node configuration file: " + e.message);
+  }
   // prepare the header
   var post_headers = {
     'Content-Type'  : 'application/json'