oops.. used abs instead of fabs from math library

treeherder/webapp/api/logslice.py

@@ -38,8 +38,8 @@ class LogSliceView(viewsets.ViewSet):
         gz_file = None
 
         try:
-            start_line = math.abs(int(request.QUERY_PARAMS.get("start_line", 0)))
-            end_line = math.abs(int(request.QUERY_PARAMS.get("end_line", 0)))
+            start_line = math.fabs(int(request.QUERY_PARAMS.get("start_line", 0)))
+            end_line = math.fabs(int(request.QUERY_PARAMS.get("end_line", 0)))
         except Exception as e:
             return Response("parameters could not be converted to integers", 400)