Revert combobox onblur pill creation in #1353 (#1363)

Reverts #1353

CHANGELOG.md

@@ -6,6 +6,7 @@
 **Bug fixes**
 
 - `react-datepicker` set milliseconds to zero when selecting time ([#1361](https://github.com/elastic/eui/pull/1361))
+- Revert ([#1353](https://github.com/elastic/eui/pull/1353)) `onBlur` action on `euiComboBox`. It caused regressions on Kibana. ([#1363](https://github.com/elastic/eui/pull/1363))
 
 ## [`5.5.1`](https://github.com/elastic/eui/tree/v5.5.1)
 
@@ -15,7 +16,7 @@
 
 ## [`5.5.0`](https://github.com/elastic/eui/tree/v5.5.0)
 
-**Note: this release broke the exported TypeScript definitions. This is fixed in `5.5.1`.**
+**Note: this release broke the exported TypeScript definitions and `EuiComboBox` in certain situations. These are both fixed in `5.5.2`.**
 
 - Altered functionality of `truncate` on `EuiBreadcrumbs` and added `truncate` ability on breadcrumb item ([#1346](https://github.com/elastic/eui/pull/1346))
 - Altered `EuiHeader`'s location of `EuiHeaderBreadcrumbs` based on the new `truncate` ability ([#1346](https://github.com/elastic/eui/pull/1346))

src/components/combo_box/combo_box.js

@@ -258,12 +258,6 @@ export class EuiComboBox extends Component {
       this.closeList();
     }
 
-    // If the user tabs away or changes focus to another element, take whatever input they've
-    // typed and convert it into a pill, to prevent the combo box from looking like a text input.
-    if (!this.hasActiveOption()) {
-      this.addCustomOption();
-    }
-
     if (this.props.onBlur) {
       this.props.onBlur(e);
     }