Rolled back removing inline source map for plugins build

Summary: After some testing I found file source map does not work as expected when prod version of Flipper is used to debug plugin. So returning back inline source maps. Note that this only affects debug builds, for production builds no source maps will be produced anyway.

Reviewed By: passy

Differential Revision: D22161927

fbshipit-source-id: 068b9da09da4dcb6c31aff4e5a15bd6438f686b3

desktop/pkg-lib/src/runBuild.ts

@@ -35,9 +35,7 @@ export default async function runBuild(
   out: string,
   dev: boolean,
 ) {
-  const sourceMapUrl = path.basename(
-    out.substring(0, out.lastIndexOf('.')) + '.map',
-  );
+  const sourceMapUrl = null; // inline source map
   const baseConfig = await Metro.loadConfig();
   const config = Object.assign({}, baseConfig, {
     reporter: {update: () => {}},