Allow equals sign in single-line ini variables

# Description/reproduce
Add a base64-encoded variable to the inventory hosts file (note the equals sign):
```
neptun auth="YWRtaW46YWRtaW4="
```

Running `ansible-playbook -i hosts` leads to an exception thrown.
```
Invalid ini entry: auth=YWRtaW46YWRtaW4= - too many values to unpack
```

PR fixes the issue.