fix: rust-tools.nvim not found (kawre#46)

Author: herschel-ma

lua/leetcode-ui/question.lua

@@ -91,7 +91,9 @@ function Question:handle_mount()
     vim.cmd("$tabe " .. self.file:absolute())
 
     -- https://github.com/kawre/leetcode.nvim/issues/14
-    if self.lang == "rust" then pcall(require("rust-tools.standalone").start_standalone_client) end
+    if self.lang == "rust" then
+        pcall(function() require("rust-tools.standalone").start_standalone_client() end)
+    end
 
     self.bufnr = vim.api.nvim_get_current_buf()
     self.winid = vim.api.nvim_get_current_win()