Fix missing marketplace issue for eclipse

I ran into a weird issue in eclipse, where the ‘marketplace’ menu is gone from the Help menu.

By some research, this seems to be the way to resolve it.

• Open your eclipse.ini (The path is /Applications/Eclipse\ JEE.app/Contents/Eclipse/ on mac)
• Add the following at the top:

-clean
-initialize

• Start your Eclipse once (it will stop on its own after a moment)
• Remove those entries again and restart Eclipse
• Check if the Marketplace entry is there now