Hide password when raising error

[bbaugher]

Without this I would get this,

zabbixapi/lib/zabbixapi/client.rb:108:in `_request': Server answer API error (ZabbixApi::ApiError)
 {
  "code": -32602,
  "message": "Invalid params.",
  "data": "Login name or password is incorrect."
}
 on request:
 {
  "method": "user.login",
  "params": {
    "user": "Admin",
    "password": "zabbix"
  },
  "id": 55213,
  "jsonrpc": "2.0"
}

With this change its now,

zabbixapi/lib/zabbixapi/client.rb:108:in `_request': Server answer API error (ZabbixApi::ApiError)
 {
  "code": -32602,
  "message": "Invalid params.",
  "data": "Login name or password is incorrect."
}
 on request:
 {
  "method": "user.login",
  "params": {
    "user": "Admin",
    "password": "***"
  },
  "id": 69191,
  "jsonrpc": "2.0"
}

[aladmit]

Thank you @bbaugher