LanguageClient broken starting with 4.14.1

Rust-analyzer works perfectly with all versions before 4.14.1

4.14.1 mentions some "Fixed handling of dynamically registered capabilities"

This broke Rust-analyzer, starting with 4.14.1 line annotations only contain warnings and errors related to braces/endline, and just disappear after changing code in the text editor for a bit.

Any actual errors such as for example ```let g: u32 = 12.2;``` aren't displayed.