Allow URL to be stripped
diff --git a/tools/mirror_check.rb b/tools/mirror_check.rb
index c57deed..ce6a31d 100755
--- a/tools/mirror_check.rb
+++ b/tools/mirror_check.rb
@@ -370,7 +370,7 @@
 
 if __FILE__ == $0
   init
-  url = ARGV[0] || "localhost" # easier to test in an IDE
+  url = ""+ARGV[0] || "localhost" # easier to test in an IDE
   checkHTTP(url)
   # display the test results
   @tests.each { |t| t.map{|k, v| puts "#{k}: - #{v}"}}