Merge #10469: Fixing typo in rpcdump.cpp

Summary:
16d94d3 Fixing typo in rpcdump.cpp (James Evans)

Tree-SHA512: 84ef1b91c719131196ebed6b865e282b77bee7699614e15884ba59010239a3bbc1380dc8f856c83338f071e3eb3ca41c6b10f830816e6c794531cf6a965d63a9

Backport of Core PR10469
https://github.com/bitcoin/bitcoin/pull/10469

Test Plan:

make check
test_runner.py

Reviewers: jasonbcox, deadalnix, Fabien, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: deadalnix, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3238