fix: column could be < 1 when wrapper taken into account

[bcoe]

In Node.js 10, it was possible for the column position to be less than 1 after subtracting the wrapper; this problem should go away once nodejs/node#27124 is released.

[coveralls]

Pull Request Test Coverage Report for Build 80

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 93.722%

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Totals
Change from base Build 78:	0.0%
Covered Lines:	151
Relevant Lines:	157

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 80

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 93.722%

---

Totals
Change from base Build 78:	0.0%
Covered Lines:	151
Relevant Lines:	157

---

💛 - Coveralls