using sql_service within deinit of plugin segfaults on shutdown

(gdb) bt full

#0  0x00007f1bd80ae834 in __pthread_kill_implementation () from /lib64/libc.so.6

No symbol table info available.

#1  0x000000000107f9dc in handle_fatal_signal (sig=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/sql/signal_handler.cc:369

        curr_time = <optimized out>

        print_invalid_query_pointer = <optimized out>

        thd = 0x52b000093208

        tm = <optimized out>

#2  <signal handler called>

No symbol table info available.

#3  0x0000000000a68e24 in intern_plugin_lock (lex=0x0, rc=0x0, state_mask=14)

    at /home/dan/repos/mariadb-server-10.4/sql/sql_plugin.cc:952

        pi = 0x0

#4  plugin_thdvar_init (thd=0x52b000093208) at /home/dan/repos/mariadb-server-10.4/sql/sql_plugin.cc:3249

        old_table_plugin = 0x0

        old_tmp_table_plugin = 0x0

        old_enforced_table_plugin = 0x0

#5  0x0000000000926976 in THD::init (this=0x52b000093208) at /home/dan/repos/mariadb-server-10.4/sql/sql_class.cc:1214

No locals.

#6  0x00000000009251cb in THD::THD (this=0x52b000093208, id=<optimized out>, is_wsrep_applier=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/sql/sql_class.cc:809

        old_THR_THD = 0x0

        tmp = <optimized out>

#7  0x0000000000a8f94b in mysql_real_connect_local (mysql=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/sql/sql_prepare.cc:6207

        thd_orig = 0x0

        client_flag = 131072

        new_thd = <optimized out>

        p = <optimized out>

#8  0x00007f1bd5c04a4d in run_sql (query_len=18, query=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/plugin/example_keymgt_sql_service/example_keymgt_sql_service.cc:19

        mysql = 0x51a000026a88

#9  example_keymgt_sql_service_deinit (p=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/plugin/example_keymgt_sql_service/example_keymgt_sql_service.cc:59

No locals.

#10 0x0000000000f3b0dd in finalize_encryption_plugin (plugin=0x521000030e58)

    at /home/dan/repos/mariadb-server-10.4/sql/encryption.cc:121

        used = <optimized out>

#11 0x0000000000a5f643 in plugin_deinitialize (plugin=0x521000030e58, ref_check=<optimized out>)

    at /home/dan/repos/mariadb-server-10.4/sql/sql_plugin.cc:1244

No locals.

#12 0x0000000000a60ec9 in plugin_shutdown () at /home/dan/repos/mariadb-server-10.4/sql/sql_plugin.cc:2104

        count = <optimized out>

        i = 54

        plugin = <optimized out>

        plugins = 0x7ffcefbffc20

        dl = <optimized out>

#13 0x00000000007a10b5 in clean_up (print_message=<optimized out>) at /home/dan/repos/mariadb-server-10.4/sql/mysqld.cc:2010

No locals.

#14 0x00000000007a8621 in mysqld_main (argc=<optimized out>, argv=0x51b000000ee8)

    at /home/dan/repos/mariadb-server-10.4/sql/mysqld.cc:5979

        ho_error = <optimized out>

        new_thread_stack_size = <optimized out>

        user = 0x504000010958 "root[root] @ localhost [127.0.0.1]"

        please_close_stdin = <optimized out>