[fix] hash plugin

searx/plugins/hash_plugin.py

 
     # select hash function
     f = hashlib.new(function.lower())
-    #f = hash_function[function.lower()]
 
     # make digest from the given string
     f.update(string.strip())
     # print result
     search.result_container.answers.clear()
     search.result_container.answers.add(function + " " + gettext('hash function') + ": " + digest)
-    return True
+    return True