[TRIVIAL] Fixes for gcc 10

[seelabs]

Gcc 10 fails to compile rippled without this change.

[codecov-io]

Codecov Report

Merging #3393 into develop will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #3393      +/-   ##
===========================================
- Coverage    70.44%   70.43%   -0.02%     
===========================================
  Files          682      682              
  Lines        54392    54392              
===========================================
- Hits         38315    38309       -6     
- Misses       16077    16083       +6     

Impacted Files	Coverage Δ
src/ripple/rpc/handlers/AccountTx.cpp	85.23% <100.00%> (ø)
src/ripple/server/impl/BaseHTTPPeer.h	85.96% <0.00%> (-3.51%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9771210...1cca80e. Read the comment docs.