Updated README user-agent to 0.4.9

Author: urbanadventurer

README

@@ -122,7 +122,7 @@ AGGRESSION:
       all plugins are used for all URLs.
 
 HTTP OPTIONS:
-  --user-agent, -U=AGENT Identify as AGENT instead of WhatWeb/0.4.8-dev.
+  --user-agent, -U=AGENT Identify as AGENT instead of WhatWeb/0.4.9.
   --header, -H          Add an HTTP header. eg "Foo:Bar". Specifying a default
                         header will replace it. Specifying an empty value, eg.
                         "User-Agent:" will remove the header.
@@ -202,7 +202,7 @@ HELP & MISCELLANEOUS:
   --short-help            Short usage help.
   --help, -h              Complete usage help.
   --debug                 Raise errors in plugins.
-  --version               Display version information. (WhatWeb 0.4.8-dev).
+  --version               Display version information. (WhatWeb 0.4.9).
 
 EXAMPLE USAGE:
 * Scan example.com.