fix doCall if args.From is nil

[noot]

Closes: #XXX

Description

• if args.From is nil when doing a call, set it to the first account address
• previously would haven't set it

---

For contributor use:

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

---

For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (development@fe99e7e). Click here to learn what that means.
The diff coverage is n/a.

@@              Coverage Diff               @@
##             development     #518   +/-   ##
==============================================
  Coverage               ?   70.49%           
==============================================
  Files                  ?       41           
  Lines                  ?     2325           
  Branches               ?        0           
==============================================
  Hits                   ?     1639           
  Misses                 ?      543           
  Partials               ?      143           

---

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 fe99e7e...93d4f35. Read the comment docs.