Fix a vulnerability regarding character deletion

[Troughy]

Describe Pull request
This will disallow cheaters (anyone with a LUA script executor) from deleting their characters, bypassing the Config.EnableDeleteButton setting. This is done by simply making sure Config.EnableDeleteButton is true, before deleting the character in qb-multicharacter:server:deleteCharacter

If your PR is to fix an issue mention that issue here
#253

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? yes
• Does your code fit the style guidelines? yes
• Does your PR fit the contribution guidelines? yes