when we receive intentional empty whats new info, do not try to show it

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

lib/private/Updater/ChangesCheck.php

@@ -55,7 +55,11 @@ class ChangesCheck {
 	public function getChangesForVersion(string $version): array {
 		$version = $this->normalizeVersion($version);
 		$changesInfo = $this->mapper->getChanges($version);
-		return json_decode($changesInfo->getData(), true);
+		$changesData = json_decode($changesInfo->getData(), true);
+		if(empty($changesData)) {
+			throw new DoesNotExistException();
+		}
+		return $changesData;
 	}
 
 	/**

tests/lib/Updater/ChangesCheckTest.php

@@ -279,6 +279,10 @@ class ChangesCheckTest extends TestCase {
 					],
 				]
 			],
+			[ # 4 - empty
+				'',
+				[]
+			],
 		];
 	}