Handle curl exception scenario

The `execCurl` function has the potential to return null which was not properly being handled downstream.

Author: apm963

cmds/curlx.js

@@ -5,6 +5,10 @@ const { execCurl } = require('../utils/execute-curl.js');
 
 module.exports = async (args, exec_str, db) => {
   let cx_response = await execCurl(exec_str);
+  if (!cx_response) {
+    outputResponse(`Error while executing ${exec_str}`);
+    return;
+  }
   outputResponseHeaders(cx_response.responseHeaders);
   outputResponse(cx_response.responseBody);
   if (cx_response.logData) {