address review

Co-authored-by: Jean-Yves <[email protected]>
Signed-off-by: Simon L. <[email protected]>

php/src/Docker/DockerActionManager.php

@@ -736,7 +736,7 @@ public function GetCurrentChannel() : string {
             $output = json_decode($this->guzzleClient->get($url)->getBody()->getContents(), true);
             $containerChecksum = $output['Image'];
             $tagArray = explode(':', $output['Config']['Image']);
-            if (isset($tagArray[1])) {
+            if (count($tagArray) ===  2) {
                 $tag = $tagArray[1];
             } else {
                 error_log("No tag was found when getting the current channel. You probably did not follow the documentation correctly. Changing the channel to the default 'latest'.");