[Bug-Candidate]: Slither python API went wrong when multiple SPDX license

### Describe the issue:

I downloaed the smart contracts source code and use slither to detect them in python. But the smart contract which have two different SPDX license in its two subcontracts. So the Slither('EPEPE.sol') went wrong. The error is multiple SPDX license.
https://etherscan.io/address/0xcd8d706ada4fd5c540e47d98f126f991813c44ed#code

### Code example to reproduce the issue:

```
from slither.slither import Slither
cts=Slither('EPEPE.sol')
```

### Version:

0.10.3

### Relevant log output:

```shell
Multiple SPDX license
```