Fix Nimgrab (#21918)

* .

* Fix nimgrab client not closing

* Fix nimgrab client not closing

* Fix nimgrab client not closing

tools/nimgrab.nim

@@ -1,13 +1,20 @@
 import std/[os, httpclient]
 
 proc syncDownload(url, file: string) =
-  var client = newHttpClient()
+  let client = newHttpClient()
   proc onProgressChanged(total, progress, speed: BiggestInt) =
-    echo "Downloading " & url & " " & $(speed div 1000) & "kb/s"
-    echo clamp(int(progress*100 div total), 0, 100), "%"
+    var message = "Downloading "
+    message.add url
+    message.add ' '
+    message.addInt speed div 1000
+    message.add "kb/s\n"
+    message.add $clamp(int(progress * 100 div total), 0, 100)
+    message.add '%'
+    echo message
 
   client.onProgressChanged = onProgressChanged
   client.downloadFile(url, file)
+  client.close()
   echo "100%"
 
 if os.paramCount() != 2: