[FIXED] startingBase.rul issue when defining non random soldiers

[Meridian]

startingBase.rul when defining non random soldiers with random soldiers the soldier "id:"s will not be unique

reported here: https://github.com/OpenXcom/OpenXcom/issues/1451

[Meridian]

Fixed in OXCE: https://github.com/MeridianOXC/OpenXcom/commit/5c83b1bc957387e8d31b681a941937b52d14cf3e

Note that non-random soldiers have to have IDs starting with 1 and not skip any IDs.
(same as starting crafts)

For example if you have 4 non random starting soldiers, they must have IDs: 1, 2, 3 and 4