txscript: fix typos

[hieblmi]

Fix typos in script.go.

[coveralls]

Pull Request Test Coverage Report for Build 4752835809

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.002%) to 55.27%

---

Files with Coverage Reduction	New Missed Lines	%
connmgr/connmanager.go	1	86.27%
<!--	Total:	1		-->

Totals
Change from base Build 4493914678:	-0.002%
Covered Lines:	26649
Relevant Lines:	48216

---

💛 - Coveralls

[kcalvinalvin]

ACK 2c0e6d984ab844716010280d1069df70ffe84f82

[guggero]

Not sure why the unit tests failed on this and I can't trigger them manually. Can you do a rebase or commit timestamp update to re-trigger CI please?

[hieblmi]

I've changed the commit message @guggero.