message: restore necessary comman in documentation of dump
diff: @@ -9056,7 +9056,7 @@ class basic_json
  @complexity Linear.
  @liveexample{The following example shows the effect of different @a indent
  - parameters to the result of the serialization.dump}
  + parameters to the result of the serialization.,dump}
  @see https://docs.python.org/2/library/json.html#json.dump
  