Add exception so ruby wpscan.rb http://domain.com is detected

wpscan.rb

@@ -14,9 +14,14 @@ def main
     wpscan_options = WpscanOptions.load_from_arguments
 
     unless wpscan_options.has_options?
+      # first parameter only url?
+      if ARGV.length == 1
+        wpscan_options.url = ARGV[0]
+      else
         usage()
         raise('No argument supplied')
       end
+    end
 
     # Define a global variable
     $COLORSWITCH = wpscan_options.no_color