feat(contract-verifier): Allow sc code reverification (matter-labs#1455)

## What ❔

 Allow sc code reverification

## Why ❔

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## Checklist

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- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
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core/lib/zksync_core/src/api_server/contract_verification/api_impl.rs

@@ -48,14 +48,6 @@ impl RestApi {
                 HttpResponse::BadRequest().body("There is no deployed contract on this address")
             );
         }
-        if storage
-            .contract_verification_dal()
-            .is_contract_verified(request.contract_address)
-            .await
-            .unwrap()
-        {
-            return Ok(HttpResponse::BadRequest().body("This contract is already verified"));
-        }
 
         let request_id = storage
             .contract_verification_dal()