RF: Change default URL to FSL course data manifest

fsl/scripts/fsl_add_module.py

@@ -112,7 +112,7 @@ from   fsl.add_module.messages        import (info,
                                               UNDERLINE)
 
 
-MANIFEST_URL = 'http://fsl.fmrib.ox.ac.uk/fsldownloads/manifest.txt'
+MANIFEST_URL = 'http://fsl.fmrib.ox.ac.uk/fslcourse/downloads/manifest.json'
 """Location of the official FSL plugin manifest file, downloaded if an
 alternate manifest file is not specified.
 """