UNC path update

[ryfon]

Since this update I now receive '[org.eclipse.lemminx.uriresolver.InvalidURIException] Unsupported 'file' protocol' error when opening any files located on network paths.

[angelozerr]

@datho7561 could you please take care of this issue. Thanks.

[angelozerr]

@ryfon could you give an xml sample

[ryfon]

example.zip