syscolumn table: results of select with where clause are affected by encoding/collation of the system

Selects from calpontsys.syscolumn work incorrectly when system default encoding/collation is not ASCII

That breaks callastinsertid(''); function, because it relies on selects from calpontsys.syscolumn

Expected result:
Request like
select columnname, nextvalue from calpontsys.syscolumn where schema = 'test' and tablename = 'foo' and autoincrement='y';
should return only 0 or 1 results, because only one autoincrement column per table is allowed.

Actual result: (I've managed to reproduce it only on drone's runners hosts)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and tablename = 'foo' and autoincrement='y';
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2 rows in set (2.996 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and tablename = 'foo' and autoincrement='n';
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2 rows in set (0.020 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and autoincrement like 'y';
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1 row in set (1.216 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and autoincrement like '%y%';
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1 row in set (1.967 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and autoincrement = '%y%';
Empty set (0.531 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and autoincrement like 'y%';
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1 row in set (0.004 sec)

MariaDB [test]> select columnname, autoincrement, nextvalue from calpontsys.syscolumn where schema = 'test' and tablename = 'foo' and autoincrement like 'y';
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1 row in set (0.008 sec)