fix issue #8323

	harmonic(n).evalf() and catalan(n).evalf()
Is this an intended change? Because in master, the way to get this is by passing the keyword `rational=False`, I believe.

```
>>> e
3.0*sqrt(2)
>>> e.as_coeff_mul()
(1, (3.00000000000000, sqrt(2)))
>>> e.as_coeff_mul(rational=0)
(3.00000000000000, (sqrt(2),))
```