finance/ticker: update to 4.5.6

[fuz]

Summary

finance/ticker: update to 4.5.6

 - fix build on riscv64 by bumping golang.org/x/sys dependency to v0.5.0

Changelog: https://github.com/achannarasappa/ticker/releases/tag/v4.5.6

Sponsored by:	Berliner Linux User Group e.V.
Approved by:	... (mentor)

Test Plan

Tested with Poudriere on riscv64 FreeBSD 13.1 (no log file available).
Tested with Poudriere on i386 amd64 FreeBSD 12.4 13.1.
Arm64 test results pending. For logs see
http://fuz.su/~fuz/freebsd/batch3

[eduardo]

+ MFH, new version have fixes