fix: gas config is set to zero in ibc transfer keeper

[yihuang]

Description

Solution:

• it's better to be safe unless there's good reason for that.

Closes: #969

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• tackled an existing issue or discussed with a team member
• left instructions on how to review the changes
• targeted the main branch

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.63%. Comparing base (83a3a6c) to head (e56904a).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #968      +/-   ##
==========================================
+ Coverage   65.56%   65.63%   +0.06%     
==========================================
  Files         319      319              
  Lines       22220    22207      -13     
==========================================
+ Hits        14569    14576       +7     
+ Misses       6480     6470      -10     
+ Partials     1171     1161      -10     

Files with missing lines	Coverage Δ
x/erc20/keeper/ibc_callbacks.go	93.04% <ø> (-0.18%)	⬇️
x/ibc/transfer/keeper/msg_server.go	100.00% <ø> (ø)

... and 3 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.