fix: prop window is not defined in web worker (#1749)

Author: robertsLando

esbuild.js

@@ -16,9 +16,6 @@ const options = {
     platform: 'browser',
     globalName: 'mqtt',
     sourcemap: false, // this can be enabled while debugging, if we decide to keep this enabled we should also ship the `src` folder to npm
-    define: {
-        'global': 'window'
-    },
     plugins: [
         polyfillNode({
             polyfills: [