pt-table-checksum should force replica table charset to utf8

Background information:

https://groups.google.com/forum/#!topic/percona-discussion/uOSGA6P6BIU

I am suggesting to change:

  CREATE TABLE checksums (
     db CHAR(64) NOT NULL,
     tbl CHAR(64) NOT NULL,
     chunk INT NOT NULL,
     chunk_time FLOAT NULL,
     chunk_index VARCHAR(200) NULL,
     lower_boundary TEXT NULL,
     upper_boundary TEXT NULL,
     this_crc CHAR(40) NOT NULL,
     this_cnt INT NOT NULL,
     master_crc CHAR(40) NULL,
     master_cnt INT NULL,
     ts TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     PRIMARY KEY (db, tbl, chunk),
     INDEX ts_db_tbl (ts, db, tbl)
  ) ENGINE=InnoDB;

to

  CREATE TABLE checksums (
     db CHAR(64) NOT NULL,
     tbl CHAR(64) NOT NULL,
     chunk INT NOT NULL,
     chunk_time FLOAT NULL,
     chunk_index VARCHAR(200) NULL,
     lower_boundary TEXT NULL,
     upper_boundary TEXT NULL,
     this_crc CHAR(40) NOT NULL,
     this_cnt INT NOT NULL,
     master_crc CHAR(40) NULL,
     master_cnt INT NULL,
     ts TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     PRIMARY KEY (db, tbl, chunk),
     INDEX ts_db_tbl (ts, db, tbl)
  ) ENGINE=InnoDB charset=utf8;

or at least

  CREATE TABLE checksums (
     db CHAR(64) NOT NULL charset utf8,
     tbl CHAR(64) NOT NULL charset utf8,
     chunk INT NOT NULL,
     chunk_time FLOAT NULL,
     chunk_index VARCHAR(200) NULL,
     lower_boundary TEXT NULL,
     upper_boundary TEXT NULL,
     this_crc CHAR(40) NOT NULL,
     this_cnt INT NOT NULL,
     master_crc CHAR(40) NULL,
     master_cnt INT NULL,
     ts TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     PRIMARY KEY (db, tbl, chunk),
     INDEX ts_db_tbl (ts, db, tbl)
  ) ENGINE=InnoDB;

As the table names have to be utf8 (character_set_system). By leaving it as default, on systems with default charset binary, CHAR(64) gets converted into BINARY(64) and checksums fail because padded space is not deleted by default in db and table names on fetch function ('my_table_name\0\0\0\0\0\0').

Surprisingly the CREATE TABLEs are applied directly from the ones documented on the same file. Changing the embbebed man at the beginning of the file fixed the issue for me. But I would like the change to be applied upstream. It is a very trivial change, just make sure with your CI that nothing else breaks.