use server.agents() mediaType keyword to shorten code

Thanks @JonnyWong16

Author: blacktwin

plexapi/library.py

@@ -407,12 +407,7 @@ def all(self, sort=None, **kwargs):
     def agents(self):
         """ Returns a list of available `:class:`~plexapi.media.Agent` for this library section.
         """
-        results = []
-        for agent in self._server.agents():
-            for agentType in agent.mediaTypes:
-                if agentType.mediaType == utils.searchType(self.type):
-                    results.append(agent)
-        return results
+        return self._server.agents(utils.searchType(self.type))
 
     def settings(self):
         """ Returns a list of all library settings. """