incorrectly assigned statistics for skills

[Eur0x]

Describe the bug
incorrectly assigned statistics - for example, if we enter something like this in config:

  rewards:
    - "strength::1:1:2"
    - "strength::2:3:4"
    - "strength::3:4:5"
    - "strength::4:6:7"
    - "strength::5:8:9"
    - "strength::6:10:11"

then when we reach the first skill level, we get +6 strength (we should get +1 strength for level 1 and 2)

To Reproduce
Steps to reproduce the behavior:

1. Go to 'skills folder'
2. Click on 'any config'
3. Scroll down to 'rewards / replace with config above'
4. See error

Expected behavior
we should get +1 strength for level 1 and 2 (from config above)

Screenshots

Server Information (please complete the following information):

• Version: (output of /ver command) - Paper version git-Paper-4 (MC: 1.19) (Implementing API version 1.19-R0.1-SNAPSHOT) (Git: 8b6f4dd)
• Version of plugin and eco (/ver eco - 1.4.2 /ver <plugin> - EcoSkills v1.42.0)

Additional context

• none