Fix os.path.join call

This call prevents nearly all data translation when using a
directory-based endpoint (i.e. not maven coordinates), because the
converter executing the problematic call is of very high priority.

src/napari_imagej/types/converters/trackmate.py

@@ -22,7 +22,7 @@ def trackmate_present():
         return True
     # Step 2 - check the jar directory
     elif isdir(join(endpoint, "jars")):
-        for fname in listdir(join([endpoint, "jars"])):
+        for fname in listdir(join(endpoint, "jars")):
             if match("TrackMate-\d.*\.jar", fname):  # noqa
                 return True
     return False