Use concatenation to build the cdn url for the browser snippet (#1260)

Author: matux

src/browser/bundles/defaults.js

@@ -1,4 +1,5 @@
 import { version } from '../../defaults.js'
 
 export const cdnHost = 'cdn.rollbar.com';
-export const defaultRollbarJsUrl = `https://${cdnHost}/rollbarjs/refs/tags/v${version}/rollbar.min.js`;
+// concatenation over interpolation makes the minified file smaller
+export const defaultRollbarJsUrl = 'https://' + cdnHost + '/rollbarjs/refs/tags/v' + version + '/rollbar.min.js';