Crash when slave is lagging

[renecannao]

Crashing bug related to replication lag check

(gdb) bt
#0  0x00007f4275c04811 in __strlen_sse2_pminub () from /lib64/libc.so.6
#1  0x0000000000470387 in ProxySQL_Admin::save_mysql_servers_runtime_to_database (this=0x7f42740251c0, _runtime=false) at ProxySQL_Admin.cpp:3848
#2  0x000000000044fcb7 in MySQL_HostGroups_Manager::read_only_action (this=0x7f4274059000, hostname=0x7f426f41b170 "192.168.0.5", port=3306, read_only=0) at MySQL_HostGroups_Manager.cpp:1083
#3  0x00000000004828c0 in MySQL_Monitor::monitor_read_only (this=0x7f4274179210) at MySQL_Monitor.cpp:1293
#4  0x00007f4276430220 in ?? () from /lib64/libstdc++.so.6
#5  0x00007f4277301df5 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f4275b981ad in clone () from /lib64/libc.so.6