fix: try to fix install.lua mistakes

lua/Trans/core/install.lua

@@ -5,29 +5,34 @@ return function()
     -- INFO :Check ultimate.db exists
     local dir = Trans.conf.dir
     local path = dir .. '/ultimate.db'
+
     local fn = vim.fn
+    if fn.isdirectory(dir) == 0 then
+        fn.mkdir(dir, 'p')
+    end
 
     if fn.filereadable(path) == 1 then
         vim.notify('Database already exists', vim.log.WARN)
         return
-    else
-        vim.notify('Trying to download database', vim.log.INFO)
     end
 
+    vim.notify('Trying to download database', vim.log.INFO)
 
     -- INFO :Download ultimate.db
     local uri = 'https://github.com/skywind3000/ECDICT-ultimate/releases/download/1.0.0/ecdict-ultimate-sqlite.zip'
-    local loc = dir .. '/ultimate.zip'
+    local zip = dir .. '/ultimate.zip'
+    if fn.filereadable(zip) then os.remove(zip) end
+
     local handle = function(output)
-        if output.exit == 0 and fn.filereadable(loc) then
+        if output.exit == 0 and fn.filereadable(zip) then
             if fn.executable('unzip') == 0 then
-                vim.notify('unzip not found, Please unzip ' .. loc .. 'manually', vim.log.ERROR)
+                vim.notify('unzip not found, Please unzip ' .. zip .. 'manually', vim.log.ERROR)
                 return
             end
 
-            local cmd = string.format('unzip %s -d %s', path, dir)
+            local cmd = string.format('unzip %s -d %s', zip, dir)
             local status = os.execute(cmd)
-            os.remove(path)
+            os.remove(zip)
             if status == 0 then
                 vim.notify('Download database successfully', vim.log.INFO)
                 return
@@ -40,7 +45,7 @@ return function()
 
 
     Trans.curl.get(uri, {
-        output = loc,
+        output = zip,
         callback = handle,
     })