Change test to reflect renaming

Change what string the TestWorkerKeyChange-test is looking for, to reflect the new Propose-worker msg-changes

cmd/lotus-miner/actor_test.go

@@ -72,7 +72,7 @@ func TestWorkerKeyChange(t *testing.T) {
 	result := output.String()
 	output.Reset()
 
-	require.Contains(t, result, fmt.Sprintf("Worker key change to %s successfully proposed.", newKey))
+	require.Contains(t, result, fmt.Sprintf("Worker key change to %s successfully sent", newKey))
 
 	epochRe := regexp.MustCompile("at or after height (?P<epoch>[0-9]+) to complete")
 	matches := epochRe.FindStringSubmatch(result)