fix(legacy-plugin-world-map): set useLegacyApi to true by default

[villebro]

🐛 Bug Fix

The World Map plugin is currently failing if the new chart data API is enabled in Superset due to useLegacyApi not being explicitly set to true.

@rusackas @kristw @suddjian @ktmud

[vercel]

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[codecov]

Codecov Report

Merging #444 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #444   +/-   ##
=======================================
  Coverage   22.20%   22.20%           
=======================================
  Files         264      264           
  Lines        6500     6500           
  Branches      588      588           
=======================================
  Hits         1443     1443           
  Misses       5020     5020           
  Partials       37       37           

Impacted Files	Coverage Δ
plugins/legacy-plugin-chart-world-map/src/index.js	0.00% <ø> (ø)

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