Update isLatest() (#1253)

* Update isLatest()

Use the canInstall attribute to determine if the release is the latest build.

* use of utils.cast

Co-authored-by: JonnyWong16 <[email protected]>

---------

Co-authored-by: JonnyWong16 <[email protected]>

Author: BenjaminOddou

plexapi/server.py

@@ -630,8 +630,8 @@ def checkForUpdate(self, force=True, download=False):
 
     def isLatest(self):
         """ Check if the installed version of PMS is the latest. """
-        release = self.checkForUpdate(force=True)
-        return release is None
+        release = self.query('/updater/status')
+        return utils.cast(bool, release.get('canInstall'))
 
     def installUpdate(self):
         """ Install the newest version of Plex Media Server. """