Fix test 'Do not remove whitespace after number'

The Python version changed the wrong variable, which means that the
test fails.

This patch changes the variable from '_flags.whitespace_before' to
'_output.space_before_token'.

python/jsbeautifier/javascript/beautifier.py

@@ -1603,7 +1603,7 @@ def handle_dot(self, current_token):
             self.handle_whitespace_and_comments(current_token, True)
 
         if re.search("^([0-9])+$", self._flags.last_token.text):
-            self._flags.whitespace_before = True
+            self._output.space_before_token = True
 
         if reserved_array(self._flags.last_token, _special_word_set):
             self._output.space_before_token = False