N°9167 Fix 'Unknown' label

setup/itopextension.class.inc.php

@@ -146,7 +146,7 @@ class iTopExtension
 		return match ($this->sSource) {
 			iTopExtension::SOURCE_MANUAL => 'Local extensions folder',
 			iTopExtension::SOURCE_REMOTE => (ITOP_APPLICATION == 'iTop') ? 'iTop Hub' : 'ITSM Designer',
-			default => 'Unknown',
+			default => '',
 		};
 	}
 }