To go with what
@willydhafi has already said, delete both and just install the latest version.
If you already had this installed then it should have asked you to overwrite an existing install and not display two versions.
What has happened here is that you have installed a version that has been packaged differently from your existing setup and so will add it as a new version and not overwrite your existing version and hence the two versions.
Simple terms, if you install a zipped plugin that has a plugin folder that contains the plugin contents in it, then that folder itself will be installed into your WordPress plugins.
If you have a zipped plugin that opens directly into the plugin contents, then WordPress will see this differently as a new version and install it in a new plugin folder and give you another version.
