Backport BUG#41613 Slave I/O status inconsistent between SHOW SLAVE STATUS and START SLAVE

There are three internal status for slave I/O thread, both
MYSQL_SLAVE_RUN_NOT_CONNECT and MYSQL_SLAVE_NOT_RUN are reported
as 'No' for Slave_IO_running of command SHOW SLAVE STATUS.

Change MYSQL_SLAVE_RUN_NOT_CONNECT to be reported as 'Connecting'.

sql/slave.cc

@@ -1848,7 +1848,8 @@ bool show_master_info(THD* thd, Master_info* mi)
     protocol->store((ulonglong) mi->rli.group_relay_log_pos);
     protocol->store(mi->rli.group_master_log_name, &my_charset_bin);
     protocol->store(mi->slave_running == MYSQL_SLAVE_RUN_CONNECT ?
-                    "Yes" : "No", &my_charset_bin);
+                    "Yes" : (mi->slave_running == MYSQL_SLAVE_RUN_NOT_CONNECT ?
+                             "Connecting" : "No"), &my_charset_bin);
     protocol->store(mi->rli.slave_running ? "Yes":"No", &my_charset_bin);
     protocol->store(rpl_filter->get_do_db());
     protocol->store(rpl_filter->get_ignore_db());