Fix deleteFile events

Previously when deleting a file, I received:
```json
{ jsonrpc: '2.0', error: 'Message misses parameters', id: 1 }
```

This was due to the missing `server` parameter that is required when sending a `deleteFile` event. This PR just adds in the missing parameter.

src/networking/messageGenerators.js

@@ -22,6 +22,7 @@ export function fileRemovalEventToMsg({ path }) {
         "jsonrpc": "2.0",
         "method": "deleteFile",
         "params": {
+            "server": "home",
             "filename": path,
         },
         "id": messageCounter++
@@ -53,4 +54,4 @@ function addLeadingSlash(path){
         return `/${path}`
     else
         return path
-}
+}