Revert "fix(tests/e2e): drop stale --gas-adjustment from ts-relayer add-gas-price"

This reverts commit f42972f.

Author: tbruyelle

tests/e2e/e2e_tsrelayer_test.go

@@ -202,6 +202,7 @@ func (s *IntegrationTestSuite) tsRelayerAddGasPrice(chainID, gasPrice string) {
 	s.executeTSRelayerCommand(ctx, []string{
 		"add-gas-price",
 		"-c", chainID,
+		"--gas-adjustment", "2.0",
 		gasPrice,
 	})
 }