BUG#52987: mysqldump fails if umask=0077

Problem: The test case mysqldump reads a file that must
be world-readable. The test did not force the file to be
world-readable, so if the tree was branched with a umask
of 0077, the test would fail.
Fix: chmod the file.

mysql-test/t/mysqldump.test

@@ -1983,6 +1983,7 @@ drop table if exists `load`;
 create table `load` (a varchar(255));
 
 --copy_file std_data/words.dat $MYSQLTEST_VARDIR/tmp/load.txt
+--chmod 0644 $MYSQLTEST_VARDIR/tmp/load.txt
 
 --exec $MYSQL_IMPORT --ignore test $MYSQLTEST_VARDIR/tmp/load.txt