fix: proxy_uri and provider_url configurations not being passed along

Author: AntoineGS

lua/copilot/client.lua

@@ -259,7 +259,7 @@ local function prepare_client_config(overrides)
   }
 
   if proxy_uri then
-    vim.tbl_extend("force", settings, {
+    settings = vim.tbl_extend("force", settings, {
       http = { ---@type copilot_settings_http
         proxy = proxy_uri,
         proxyStrictSSL = vim.g.copilot_proxy_strict_ssl or false,
@@ -269,7 +269,7 @@ local function prepare_client_config(overrides)
   end
 
   if provider_url then
-    vim.tbl_extend("force", settings, {
+    settings = vim.tbl_extend("force", settings, {
       ["github-enterprise"] = { ---@type copilot_settings_github-enterprise
         uri = provider_url,
       },