Upgrade HeidiSQL to 10.2

HeidiSQL 10.1 has been out since Jan, and the fixes since our current 9.5 include some issues which sound worth upgrading for, such as:

• Crash on 'explain anayzer on mariadb: https://github.com/HeidiSQL/HeidiSQL/issues/194
  as well as numerous other crashing issues.

HeidiSQL 10.2 is due out on June 15, and includes a MariaDB 10.4-related fix:

• Empty user list and crash on add user on MariaDB 10.4: https://github.com/HeidiSQL/HeidiSQL/issues/599
  so it may be worth waiting for 10.2