That is correct, that is a standard supported by all browsers and WordPress for quite some time. It is a protocol relative URL. This allows the asset to be loaded over either
https without browser throwing mixed content warnings.
So, in short, this is not a bug with Connections. It is a bug in WP Minify not properly supporting assets that were enqueued with protocol relative URLs. If WP Minify has an option to exclude files, then I suggest try adding this file as an exclusion. The assets loaded by Connections are already minified anyway.
Hoe that helps!