chore(clippy): fix clippy warnings

[va-an]

Description

Clippy fixes inspired by bitcoindevkit/bdk#1990

Changelog notice

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

[coveralls]

Pull Request Test Coverage Report for Build 16252272111

Details

• 0 of 12 (0.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.3%) to 2.983%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/utils.rs	0	2	0.0%
src/main.rs	0	3	0.0%
src/handlers.rs	0	7	0.0%

Totals
Change from base Build 15731603419:	0.3%
Covered Lines:	25
Relevant Lines:	838

---

💛 - Coveralls

[va-an]

Fixed in #208.