MAGETWO-97122: User Role minor changes

Author: SeruyV

app/code/Magento/User/Controller/Adminhtml/User/Role/Delete.php

@@ -36,12 +36,14 @@ public function execute()
 
             return $resultRedirect->setPath('adminhtml/*/editrole', ['rid' => $rid]);
         }
+        $role = $this->_initRole();
+        if (!$role->getId()) {
+            $this->messageManager->addError(__('We can\'t find a role to delete.'));
+
+            return $resultRedirect->setPath("*/*/");
+        }
 
         try {
-            $role = $this->_initRole();
-            if (!$role->getId()) {
-                throw new \Exception();
-            }
             $role->delete();
             $this->messageManager->addSuccess(__('You deleted the role.'));
         } catch (\Exception $e) {

app/code/Magento/User/Test/Unit/Controller/Adminhtml/User/Role/DeleteTest.php

@@ -289,7 +289,7 @@ public function testExecuteWithoutRole()
 
         $this->messageManagerMock->expects($this->once())
             ->method('addError')
-            ->with(__('An error occurred while deleting this role.'))
+            ->with(__('We can\'t find a role to delete.'))
             ->willReturnSelf();
 
         $this->resultRedirectMock->expects($this->once())