test: update test expectation

Signed-off-by: Manan Gupta <manan@planetscale.com>

go/vt/vtctl/reparentutil/emergency_reparenter_test.go

@@ -3461,7 +3461,7 @@ func TestEmergencyReparenter_reparentReplicas(t *testing.T) {
  keyspace: "testkeyspace",
  shard: "-",
  shouldErr: true,
- errShouldContain: "failed to promote zone1-0000000100 to primary: context deadline exceeded",
+ errShouldContain: "failed to promote zone1-0000000100 to primary: primary-elect tablet zone1-0000000100 failed to be upgraded to primary: context deadline exceeded",
  },
  }