Revert last checkin: _PyUnicode_New() allocates space

for one more character anyway.

Objects/unicodeobject.c

@@ -427,7 +427,7 @@ PyObject *PyUnicode_FromString(const char *u)
 	}
     }
 
-    unicode = _PyUnicode_New(size+1);
+    unicode = _PyUnicode_New(size);
     if (!unicode)
         return NULL;