MNT: convert script entry point

setup.py

@@ -127,6 +127,7 @@ setup(
             'atlasquery     = fsl.scripts.atlasq:atlasquery_emulation',
             'fsl_ents       = fsl.scripts.fsl_ents:main',
             'resample_image = fsl.scripts.resample_image:main',
+            'fsl_convert_x5 = fsl.scripts.fsl_convert_x5:main'
         ]
     }
 )