Alter spoint op family to add missed operator 17 (<->)

The upgrade script misses the altering of spoint operator family
to add operator 17. It is required for k-NN search.

Author: vitcpp

upgrade_scripts/pg_sphere--1.4.2--1.5.0.sql.in

@@ -15,6 +15,16 @@ EXCEPTION
 END;
 $$;
 
+DO $$
+BEGIN
+   ALTER OPERATOR FAMILY spoint USING gist ADD
+      OPERATOR 17 <-> (spoint, spoint) FOR ORDER BY float_ops;
+EXCEPTION
+   WHEN duplicate_object THEN NULL;
+   WHEN OTHERS THEN RAISE;
+END;
+$$;
+
 CREATE FUNCTION reset_sphere_output_precision()
    RETURNS CSTRING
    AS 'MODULE_PATHNAME', 'reset_sphere_output_precision'