Updated the wording on the warning screen for blind signing

[apaillier-ledger]

Description

To be in line with the new Figma designs.

Changes include

• Bugfix (non-breaking change that solves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)
• Tests
• Documentation
• Other (for changes that might not fit in any category)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.20%. Comparing base (b48130d) to head (c6ff915).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #747   +/-   ##
=======================================
  Coverage   60.20%   60.20%           
=======================================
  Files          12       12           
  Lines        1729     1729           
=======================================
  Hits         1041     1041           
  Misses        688      688           

Flag	Coverage Δ
unittests	60.20% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vforgeoux-ledger]

The wording looks good to me.