Problem description: An error is returned at the bottom of the Monitoring => Latest data => log or text type item history when applying a filter with empty "Items list" field for the first time.

Steps to reproduce:

1. Create a Host
2. Add an item with "type of information" set to "log" or "text"
3. Wait for the item to collect a couple of values
4. Navigate to Monitoring => Latest data , select the previously created host in filter field "Hosts" and press "Apply".
5. When the list of items is returned, press on "History" button next to the previously created item
6. In the opened view, select Filter configuration, remove the item name from field "Items list" and press "Apply"

Result: The following error is returned at the bottom of the page:

array_key_exists(): The first argument should be either a string or an integer [history.php:126 → updateTimeSelectorPeriod() → CProfile::update() → CProfile::get() → array_key_exists() → CConfigFile->{closure}() in conf/zabbix.conf.php:79]

and the following runtime error is observed:

array_key_exists(): The first argument should be either a string or an integer [history.php:126 -> updateTimeSelectorPeriod() -> CProfile::update() -> CProfile::get() -> array_key_exists() -> CConfigFile->{closure}() in include/classes/user/CProfile.php:173]

Expected: no errors should be shown, only a string "Specify some filter condition to see the values" should be returned in the resulting list of values (just as it is when pressing "Apply" for the 2nd time).

Example: