Edge case bug in update_security_group

This is truly an edge case bug, if it can be called that, in the function `update_security_group`.

If there are are IpPermissions present in the security group the code will not update the rules if `INGRESS_PORTS` changes or someone has manually deleted all rules for one value in `INGRESS_PORTS`.

**To reproduce:**
1. Set `INGRESS_PORTS = [ 80 ]`
2. Run the code
3. Set `INGRESS_PORTS = [ 80, 443 ]`
4. Run the code

**Expected behaviour:**
`IpPermissions` has been updated to include port 80 and 443

**Actual behaviour:**
Only rules for port 80 are present

I recognize that this is an edge case, and that this might not be fixed. In that case this issue will just serve as documentation of this behaviour.