Don't send invalid signatureHelp activeParameter values.

Leaving the arguments in place for when we implement the rest of the
feature.

src/fennel-ls/message.fnl

@@ -91,10 +91,9 @@ LSP json objects."
      :kind ?kind
      :edit {:changes {uri (diagnostic.quickfix)}}}))
 
-(λ symbol->signature-help [_server _file _call signature active-parameter]
+(λ symbol->signature-help [_server _file _call signature _active-parameter]
   {:signatures [signature]
-   :activeSignature 0
-   :activeParameter active-parameter})
+   :activeSignature 0})
 
 (λ multisym->range [server file ast n]
   (let [spl (utils.multi-sym-split ast)