ctypes: no need to decode bytes, should stay bytes

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73466 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/python/ctypes/preamble.py

@@ -333,7 +333,7 @@ class String(MutableString, Union):
 
         # Convert from bytes
         elif isinstance(obj, bytes):
-            return cls(decode(obj))
+            return cls(obj)
 
         # Convert from str/unicode
         elif isinstance(obj, (str, unicode)):