Zabbix

...G...... [ZBX-25798] fixed error with converting empty string to utf8

* commit 'b28f32e197351030b2b083ba64b2f584704a5560':
  ...G...... [ZBX-25798] fixed size of wide_size in case of error
  ...G...... [ZBX-25798] fixed return
  ...G...... [ZBX-25798] added debug log in case of unicode error
  ...G...... [ZBX-25798] added test with shift_jis encoded empty text
  ...G...... [ZBX-25798] fixed error with converting empty string to utf8

(cherry picked from commit 8341d62b25440cf26dd287da23f60a41e2e1babc)
(cherry picked from commit 838327712b6b61155892afcc5e2a54182e683290)