remove confused comment

Author: siddontang

pymysqlreplication/bitmap.py

@@ -3,14 +3,7 @@
 import struct
 
 class Bitmap(object):
- """ Use for current-present-bitmap1/2 in RowsEvent, copy from MySQL mysys/my_bitmap.c
- See http://dev.mysql.com/doc/internals/en/rows-event.html
- 
- null bitmap length = (bits set in 'columns-present-bitmap1'+7)/8
- null bitmap2 length = (bits set in 'columns-present-bitmap2'+7)/8
-
- We can not calculate the length using column count directly in minimal or noblob binlog row image. 
-
+ """ Use for current-present-bitmap1/2 in RowsEvent, refer to mysys/my_bitmap.c
  """ 
 
  bits2Nbits = [