Merge #2796

2796: Fix lruCapacity config key in VSCode r=kjeremy a=marcogroppo

Closes #2789.

This simply adds `null` as a valid value for the configuration key. 

We could use the server-side default value (128) instead, but in that case every time we change its value on the server side we would have to update it on the client side too.

Co-authored-by: Marco Groppo <marco.groppo@gmail.com>

editors/code/package.json

@@ -217,7 +217,10 @@
                     "description": "Trace requests to the ra_lsp_server"
                 },
                 "rust-analyzer.lruCapacity": {
-                    "type": "number",
+                    "type": [
+                        "number",
+                        "null"
+                    ],
                     "default": null,
                     "description": "Number of syntax trees rust-analyzer keeps in memory"
                 },