fix:duplicate proto import

[clockworkgr]

import "cosmos/base/v1beta1/coin.proto"; was imported twice so removed the duplicate.

Not really important but was breaking TS client code generation in Ignite CLI

Description

closes: #XXXX

Tasks

• [ ]

References

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Appropriate labels applied
• Targeted PR against correct branch
• 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
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[jaybxyz]

@clockworkgr Thank you for making this PR. Whenever there is a change in any *.proto files, we need to regenerate codes by $ make proto-gen. This requires you to install Docker.

[jaybxyz]

As I don't have permission to directly commit to this PR, I will work on this #117 and close this.

[jaybxyz]

@clockworkgr Thank you for bringing this up!