when searching for a plugin only look for a regular file

lib/ansible/utils/plugins.py

@@ -151,7 +151,7 @@ class PluginLoader(object):
 
         for i in self._get_paths():
             path = os.path.join(i, "%s%s" % (name, suffix))
-            if os.path.exists(path):
+            if os.path.isfile(path):
                 self._plugin_path_cache[name] = path
                 return path