Remove seemingly unused file sort_gtf.py.

Added in df28aec040 - not used in that commit.

tools/filters/gff/sort_gtf.py

@@ -1,20 +0,0 @@
-#!/usr/bin/env python
-import sys
-
-from galaxy.datatypes.util.gff_util import read_unordered_gtf
-
-#
-# Process inputs.
-#
-
-in_fname = sys.argv[1]
-out_fname = sys.argv[2]
-
-out = open( out_fname, 'w' )
-for feature in read_unordered_gtf( open( in_fname, 'r' ) ):
-    # Print feature.
-    for interval in feature.intervals:
-        out.write( "\t".join(interval.fields) )
-out.close()
-
-# TODO: print status information: how many lines processed and features found.