Update ConfigEntityConfigExportRule.php

Additional check to make sure the 'config_export' annotation property is need.

Author: Pasqualle

src/Rules/Deprecations/ConfigEntityConfigExportRule.php

@@ -21,7 +21,7 @@ protected function doProcessNode(ClassReflection $reflection, Node\Stmt\Class_ $
         $annotation = $reflection->getResolvedPhpDoc();
         // Plugins should always be annotated, but maybe this class is missing its
         // annotation since it swaps an existing one.
-        if ($annotation === null) {
+        if ($annotation === null || strpos('@ConfigEntityType(', $annotation->getPhpDocString()) === false) {
             return [];
         }
         $hasMatch = preg_match('/config_export\s?=\s?{/', $annotation->getPhpDocString());