[Modify] Polish it

websocket-sharp/Server/WebSocketServiceManager.cs

@@ -156,15 +156,20 @@ namespace WebSocketSharp.Server
         if (path.Length == 0)
           throw new ArgumentException ("An empty string.", "path");
 
-        if (path[0] != '/')
-          throw new ArgumentException ("Not an absolute path.", "path");
+        if (path[0] != '/') {
+          var msg = "It is not an absolute path.";
+
+          throw new ArgumentException (msg, "path");
+        }
 
         if (path.IndexOfAny (new[] { '?', '#' }) > -1) {
           var msg = "It includes either or both query and fragment components.";
+
           throw new ArgumentException (msg, "path");
         }
 
         WebSocketServiceHost host;
+
         InternalTryGetServiceHost (path, out host);
 
         return host;