Remove no longer needed index.web.dev.html

Summary: This is a duplicate, is not needed, causes confusion.

Reviewed By: aigoncharov

Differential Revision: D51307091

fbshipit-source-id: 4d55d727ea5f20100ecd15ad6e23aa0c01722524

desktop/flipper-server/src/index.tsx

@@ -190,7 +190,7 @@ async function start() {
   const {app, server, socket, readyForIncomingConnections} = await startServer(
     {
       staticPath,
-      entry: `index.web${argv.bundler ? '.dev' : ''}.html`,
+      entry: `index.web.html`,
       port: argv.port,
     },
     environmentInfo,