Integer quantity times list should not be treated as repitition count

I noticed the following weird behaviour:
```
import astropy.units as u; import numpy as np
u.Quantity(2, 'm') * ['a', 'b', 'c']
```
yields
```
['a', 'b', 'c', 'a', 'b', 'c']
```
So, the integer in the `Quantity` is taken as a repeat counter. Apparently, after `Quantity` appropriately fails to produce a multiplication, the list's `__rmul__` manages to access the array without checking the unit --- certainly `int(u.Quantity(2, 'm')` fails appropriately.