Mini-Circuits PL-258: fix typo "__" -> "_"
This PR fixes a typo where there was a double underscore "__" in the file-name and in the name of the footprint, where just a single underscore "_" was the intention.
This PR fixes a typo where there was a double underscore "__" in the file-name and in the name of the footprint, where just a single underscore "_" was the intention.